After a certain point, the excessive numbering starts to look like you're creatively bankrupt. You probably still are even if you ditch them, but at least you can hide it.
A sequel looks more creatively bankrupt than a numberless "reboot" reusing the original game's name?
Probably different degress of the same problem in terms of knee-jerk assessments. I'd say immediate numbered sequels or "trilogies" don't raise as many red flags - although the latter has become one for me, usually because it implies planning and foresight that doesn't actually exist. Even if there is, high likeliness of tripping on your dick out the gate and I'm left with a product that feels incomplete when the plan gets shitcanned (because we were saving all our great ideas and resolutions for the sequels!).
I think the way game series are often perceived (with many exceptions of course) or expected to proceed is:
Game 1 - Good ideas, some rough edges.
Game 2 - Hopefully a refinement of what people liked about 1, and minimizing/cutting out the disliked.
Game 3 - Getting a little long in the tooth and I don't know what else you can really do with this property, but I hope it's a comfortable swan song before we close the curtains.
Anything after that starts to feel uncomfortably close to Freddyson X: Fred Goes to Spacehell territory, rightly or wrongly.
Of course, perceptions change over time. Over a decade ago I wouldn't mind most attempted reboots or "reimaginings". Like, Cronenberg's "The Fly" was good, right? But lately the rate of resets have felt ridiculous, and their end-product offerings are fucking terrible and have a disturbing level of overlap in terms of their failings. And you eventually see through the trick. AssCreed Extravaganza is still basically AC10 or whatever the fuck they're at. It's just that if we're trying to put ourselves in normie shoes and give ourselves 2 seconds to react to a numbered sequel vs the subtitled one, I think people assume the latter as "fresher".
As I said though, it's all mostly a trick.