Seeing as "reboot" is an option, I just wanna say I would probably prefer a soft reboot of the movies / movie universe after 3.
I see a lot of fans asking for a 4th movie, but at the same time, there are also a lot of, idk, older viewers who are going to be very put off by a hypothethical Sonic 4 if it turns out to be dreck made just for the sake of existing.
It isn't exactly a "nobody asked for this" Toy Story 4 situation, but a lot of people are overlooking how easily it could become that way if they try to stretch it out with no love put into it. I say let's have the story refresh before we get into another movie.