iTunes is a pox. I barely use it, just have to because I've an iPhone and iPad.
But for playing my music library on my desktop, I use foobar2000 like someone also said.
And I ditched the stock music player on iOS for years now, had too many bugs and gapless playback wasn't working properly for me.
I use neutron music player as my main music player on my iPhone now, doesn't need iTunes to transfer music to and from the phone, can be done via ftp. Plays all file types too, I know a lot on here love a good flac file. Gapless playback is 100% too, I split up all mixes in seperate tracks instead of having one large file.
So yeah, you don't have to strictly use iTunes and apples music player, there's less annoying alternatives out there.