Lichess should have some sort of in depth statistics, beyond a mostly unhelpful elo/glicko rating, and the more helpful centipawn loss. A short list:
-Favorite openings
-Which openings you play well against
-Which openings you don't
-Frequently missed tactics by category
-win/loss/draw rates
-missed checkmates
-best and worst games (maybe by centipawn or opponent rating)
-lots of pretty charts
I generally agree with what you said, but why do you believe the ratings here are 'unhelpful'?
Because they don't tell you how to get better, and aren't necessarily accurate.
I would add best/worst endgames in that list too)
I personally made an excel sheet to see how i do with openings, and there were some eye openers. :D gonna feel pretty stupid to have been invested so much time in that if and when these tools get added. And i think they should.
Yes, it would be cool if lichess had more complicated ratings. My suggestion would be to instead of having the nine categories (the seven you can see if you click on your name plus puzzles and openings) they should have one rating for each speed range (bullet, blitz, classical and correspondence) and then one for each set of rules (standard/threecheck/atomic/etc) and to find your rating for eg. standard classical games, they would average your standard and classical ratings.