Is the diamond membership worth it?


no, just use lichess. Chess.com diamond is better, but not by a massive amount, and one is like 100 euro annually and the other is free
Yes, Diamond is worth it. If you want to be a Grandmaster at Chess.com by doing unlimited lessons, then Diamond is truly worth it.

I am 2400 in lichess and i also agree

you can change the depth of the engine to a higher depth i think but don't quote me
Why not?

Diamond has unlimited Insights which show trends in your games. You can use it to fix reoccurring mistakes in your games. But that requires analysis and study. I'm trying to improve my game right now so its worth an extra $6 a month to me. But, if I get to a point where I just want play and get a quick review now and again I'll drop back to platinum. Either way I like the unlimited reviews and puzzles.
well in game report(cloud) i only have the default depth of 18 ( 10 sec) and it says upgrade to diamond for more options