I really wanted to use Sailfish as Android alternative. But after reading reviews I think it is just not ready and will not be an alternative to Android and iOS any time soon. There are just too many bugs.

Linux for mobile is also not an alternative. Since there are so many apps missing it can't be compared with Android and iOS. Well at least for me this includes some banking apps that make my life just so much easier.

The only real options right now are the Android forks like LineageOS I think.