II have recently restarted piano lessons - after an interval since the last one of about 66 years.
It's not that I can't play already. I do regularly - even in public but what I am doing mainly is playing by ear. I wanted to be able to read music notation better as well as receiving some direction. Lessons and practising have changed.
Since I live in an apartment, I practise on an electronic Roland instrument using headphones. It does have the required 88 keys and fewer bells and whistles than many electronic keyboards but its grand piano sound and action is quite presentable. Lessons follow the same format in the group. We play along with the teacher who said "I learned never to ask anyone to play live because when I do they just quit." My fellow students have been with her for five or six years as beginners and they are now in the Royal Conservatory's Grade Five to Seven range. In the class the speed they prefer is much slower than mine, but as I play along I can check the accuracy and other stylistic issues.
I also like the comments that an instructor can make to adults with wider life experience and understanding. Maybe similar instruction was given to me as a child but it didn't sink in.
I like the fact that I am playing on digital piano - while above me is written notation from the page of a very old psalter or two. It unites the two musical worlds. There is no audience other than my own. It's not so much the proficiency of the playing. It's hearing what the composer intended and reaching even a tiny element of the beauty of that.