I have a 30 min piano lesson once a fortnight which feels not very much time to be formally taught that much. I feel like I actually learn more from playing around myself and other resources. But it works well for me more as useful contact with a professional musician - to have someone to show what I've been doing, add some suggestions, check I'm not missing anything or doing anything really 'wrong' etc. I would still play without them and learn new things, but they are helpful and nice.
I'm also taking some musicianship lessons at the moment and they are completely different - very structured and the teacher is frequently surprising me with new things that I don't think I could have worked out for myself.
Both are very different to the lessons I had as a child / teenager though, which I remember as just pieces, scales, exams.
If you have lessons, how do they go? There seem to be lots of ways.