RE8 was just lame. The bosses and the story in general, makes for a very stupid experience.
Honestly I think the RE series in general has hit a point of what I might call "lore overload".
Generally, this is the point where a franchise's overarching story has gone on simply too long, and the writers lost control.
The issue with making stories for a series like this is that attracting not just new players, but also returning players, means that each "episode" has to be not just built on the backs of the previous ones, but also needs to stand out more. A bit more intensity, a bit more complexity. Not all that much at once, but over time, this adds up, and eventually things get stupid.
The best example of this is probably FNAF. Started out pretty simple. Murdered kids, possessed robots, mysterious killer. Spooky stuff happens. But the series went WAY past its original intended ending. Now it's gone all sorts of bizarre. Heck the most recent entry has this giant tangled mass of metal tentacles and weird masks ("The Blob"), and it's like... how in the world did something like that end up in there? Among the other equally weird elements. This is all AFTER the time a digital entity made out of a ghost stuck to a circuit board tried to suck your mind out through your VR headset (???)
Well, the series hit lore overload awhile ago, and the writers lost the thread, so to speak. Each time needs to be bigger and more wild than the last. Not to mention that past a certain point the story also becomes very tangled, and even the writers have trouble parsing it all, because it's just got too many pieces.
Some series can get away with this with a bit of trickery (such as how the Zelda series technically has overarching lore, but each game is completely enclosed in its own story) but most cant.
When you combine this with the fact that AAA games are primarily built around spectacle (thus, the large bosses) well, the formula leads to RE8.
Really the only way out of that for the writers is a complete reboot. Not a remake, not a "retelling", a full-on reboot... starting completely from scratch, none of the already existing lore mattering anymore.
Of course, most developers/publishers aint willing to do that one.
