I've switched after 4S [1]. Yes, the lack of bought apps and general apps selection (3 years ago) was pretty disappointing. But I bought a few apps and games, navigation, set up office, video and music as subscriptions and it is working pretty fine. The point is - I've invested like 50$ to 100$ unreturnable overhead costs into Android to completely fill all my needs and and I have a backup iOS account filled with apps for a time when I want to switch back. Also it works on my tablet for now. Basically you can switch for cheap and then return a year or more after if you wish. Also consider that Android flagships cost 50%-75% of iPhone, (Sammy and Sony about the same).

[1] Battery life of new iPhones is not enough for me now and iOS can't function in low-tech, no internet environment where you need to share files and do other "geek" stuff suddenly and without PCs of any kind.