we didn't know it at the time, bot upon the release of android 7.1, nougat, we had reached the pinnacle of the technology. everything since then has either been deck chair re-arranging or the slow removal of features we once liked only to have them re-introduced 1-3 years later as a new feature. the most insulting is how completely useless google assistant became in 2020 only to now have features we had in 2014 sold to us as innovation and proof that gemini isn't a total waste of ram.
i can't speak on when iphone users hit this pinnacle, i never could figure ios out. completely unintuitive os tbh, despite what its adherents will tell you. it's mostly only intuitive if you have prior experience with apple products