Ok, this is going to be fun.
Developers "back in the day" very quickly understood that hitscan weapons being used against stationary targets were fucking boring, and the shooting itself is just so much more enjoyable due to their attempts to avoid just that. Going all the way back to Doom, basically the king of shooters, even id Software realized that shooters live primarily in the temporal space - that is, it's not just "aim at target, press fire key" that makes them fun, it's the short-term goal of setting up and executing the shots, and the long-term goal of resource management that are where the fun part lies.
Here's an example. In Unreal, firing a razorblade at a fast-moving enemy is not just about reflexes, but control, coordination and timing. You need to judge not just where to fire, but when, by figuring out on the fly, through experience, knowledge and your own skill, how long a projectile will take to reach its target, and where the target will have moved by the time the projectile reaches it. It's no coincidence that the only hitscan weapons in these older games tend to be either weak (basic pistols), limited on ammo or situational (sniper rilfes), or special power-ups, while the most powerful have significant time delays in the form of projectile movement and charge-up (such as Unreal's multi-shot rocket launcher).
One thing I like about some semi-recent shooters (not popamole trash, but stuff like STALKER), is combination of more exact collision envelopes with previously hitscan weapons (firearms) firing actual projectiles.
What we have instead are mini-games. They're called things like "press the throw grenade button when an icon appears on your HUD", "press the knife button when an enemy pops out in front of you" and so on.
Ok, I don't even want to know.
Even enemy grenade indicators piss me off to no end.
If modern shooters have one strength, it's variety. These games are expertly paced such that you're going to be seeing a new vista, a new interesting encounter, a new weapon, a new enemy type, and so on every few minutes. You rarely have to go too long without something happening. In the worst modern shooters, that's overly-scripted cutscene nonsense, but in the better ones, like Half-Life 2, the game always has something new and interesting to show you.
Ok, the fuck are you talking about?
One thing HL2 was particularly notable for at release was shit enemy and weapon variety compared to its prequel.
Environmental variety wasn't that hot either, although the environments were nice, atmospheric and gave clear sense of spatial and narrative progression.
Since FPS games aren't typically known for their compelling narratives (another area where modern shooters generally fare somewhat better), sense of spatial progression is particularly important in them.
This is achieved with diverse environment, distinct landmarks, usually environments changes having some definite direction as game progresses, and foreshadowing - it's good if you can glimpse your goal a long way before you reach it as it helps make the experience cohesive.
This is clearly evidenced in my recent shooter experiences - Unreal, though a great game, has tons of horrible levels which make so many fundamental mistakes that would never get past even the most popamole, committee-driven studio. One level in Unreal in particular that I learned to loathe is called The Sunspire. This level is a veritable maze of identical-looking corridors with no clear way forward, no good points of reference, and a complete lack of enemy and visual variety (save for one or two rooms) that make even basic navigation a chore, much less figuring out where you've been and where you need to go. Pretty sure it has respawning enemies too, so you can't even go by the trail of bodies you have left behind.
Again, the fuck are you talking about?
One thing Unreal was known for was grandeur and distinctness of its locations. Pretty much each of its 38 levels can be described with 1-2 sentences in such way that anyone who has played the game will immediately recall it. Try doing it with Quake1-2, Doom (even though Doom had some fairly distinct levels), Heretic or even DN3D.
Level design was also a strong point of Unreal - despite quite a few being fairly linear, a lot of them were anything but - huge levels with multiple alternative paths, optional content and distinct sub-locations.
Sunspire happens to count among those - while it admittedly is possible to get lost in its corridors and it could have used some more interesting interiors, it also features both multiple paths towards your objective as well as clearly defined direction of progression - of all possible directions UP is one of the less likely to lose, topped only by DOWN, because of gravity.
So,
tl;dr - yeah, you could get lost in Sunspire *IF* you wanted to explore it exhaustively - that's a good thing if exploration is involved - but you could also just go to the top without ever stopping to think about direction.
Basically you only got lost there if you wanted to.
(I know what I'm talking about, I once mapped it out on paper to make sure I haven't missed anything
- that's 'sperg for you)
There are several more such levels in Unreal, many of them full of switch puzzles.
At the best of times, these can be pretty intricate but also logical order-of-operations sorts of scenarios. Most of the time, though, they're simply set in a large, sprawling level which lacks clear landmarks for navigation, and which does not make clear what the cause and effect of your actions is (like a random lever opening a door on the other side of the map).
Again, the fuck are you talking about?
Ok, there are around 2-4 switch-hunt levels in Unreal (most notably Cellars at Dasa Pass which plays as if lifted verbatim from Quake) - out of 38.
The majority of levels, however, are either large, sprawling nonlinear ones that have few things other than enemies and space itself impeding your progress, or are linear enough to make finding the switch non-issue.
Additionally, most levels offer you hints telling you what to do in form of translator messages.
So really, accusing Unreal of switch-hunts - when they only affects 5-10% of its levels, and copypasted corridors when it's one of the few games where nearly every place is distinct from all the others is just dumb.
Now, if you were speaking of RTNP it would be true - with exceptions.
Want a switchhunt and copypasted corridors?
Go dungeon delving in Daggerfall and have fun determining which level raises which grate or trapdoor in several kilometers of interconnecting spaghetti corridors.
I also think that older shooters sometimes weren't so smart with pacing new enemies or weapon types out. In Unreal, you find pretty much every gun in the game by the halfway point through
Which is a good thing. There is nothing shittier and more annoying in an FPS than "hey, take this awesome weapon of doom! Happy? Good - now shoot this boss with it 3 times and watch the ending cutscene. Why u mad?".
In fact one of the trends I really like in FPS games is breaking up the weapon progression.
It did happen in old games too (see RL in first level of Doom 2), just not very frequently.
Sure, Call of Duty is a 5-6 hour campaign, but so are these older games if you don't stop and smell the roses or try to find every single secret.
The difference is that you could stop and smell the roses.
When I say "fuck it, I just want to finish the level", I'm often left in the situation realizing it's not clear at all where I'm supposed to go to do that.
Which is pretty much never the case with Unreal.
One thing that is bad in Unreal is weapon damage. Not weapons themselves, because those are excellent, but damage they deal is just too low.