In terms of development effort, maintaining a browser fork that merely disables these features seems pretty easy. If you think users would prefer that, why not make one?
I personally don't think it would take off, because I think most user attitudes range from "want these features" to "ambivalence". But if you're so certain, why not try?
Why does it require a fork? Having an advanced settings page with checkboxes for each of these web features seems straightforward and not overly confusing to normal users.
This, I have Safari Debug Mode on purely to disable all the annoyance. And with the current state of things there will likely never be an extension to do that.
Maintaining a fork that does that isn’t trivial, but it’s certainly doable by any one engineer.
However, maintaining such a fork is not the only prerequisite for it “taking off”. It may well be that my great uncle would love that feature - but how are you going to get his attention when several vendors are already spending millions of dollars in marketing/design/etc to influence which browser he uses?
I personally don't think it would take off, because I think most user attitudes range from "want these features" to "ambivalence". But if you're so certain, why not try?