I've played by ear since i could reach the keys on a piano. I've had 15 years of classical training. I consider myself to be an ear player rather than a music reader, partly because i trust my ears more than a lot of the music you get for popular tunes.

Having said that I find Beethoven very therapeutic and I'm not playing that by ear....

To me learning scales, arpeggios and such means I can play tunes without having to think about the mechanics of what is actually happening with my hands. I'm not going telll anyone I enjoyed it much, but it is worth it.

I had to train my ears. I could not "hear" jazz type chords until I got an Elton John book which I agree is not particularly jazzy but does have lots of chords where the bass / left hand is not related to the right band in the way it is in more classical music. Once I'd cracked that it became clear that a lot of the transcriptions in the Elton book were wrong....

And I have to agree that you do have to practise!