I actually have the “Who moved my cheese” badge on this site, and I have to say:
I don’t miss classic.
Yes, I’ve been livid lately about server crashes since we moved to the browser, and the screen rendering issues.
But we upgraded to 2023.2 a month ago, and have not had a single crash (sure is a memory hog though). And the UI issues have not gone away, but they are pretty infrequent.
Re: Customizations - I despised customizations in classic. I did like 3 and gave up. However, it’s MUCH easier to customize in App Studio. I think I actually know what I am doing in App Studio.