macOS Mojave remains my favorite macOS. Introduced dark mode support. It felt very polished to me. I used it heavily on a (now old) 2015 MBPr which some consider the last of the "original" MBP line. Sequoia followed it and dropped 32-bit support without adding anything I needed.
Same here, it's by far the most stable. After being forced to use Sequoia for the last two years and getting used to the horrible swathes of bugs, I had to pull out an old 2018 mini with Mojave on it a few days ago and nearly cried at how fast and snappy the Finder is.