I don't know enough about which parts of the site you're referring to to say for sure, but stimulus / stimulus-like approaches are perfectly fine for most display-only views even if they're fairly complex.
There are pages in our app where stimulus works great and the UI is fairly complex from a standpoint of the number of strictly user facing behavior (click this, show X, Y, and Z).
The complexity involved in handling form UI is just not very suitable for stimulus from my experience. That said, you can still do a lot in terms of following good programming practices to create something that looks and works great and is reasonably maintainable.
It ultimately comes down to your (and your teams) tolerance and business needs - there's no hard reason we need to stop using stimulus, we've just decided that there are parts of our app where we could make leaps in developer productivity by using something else.