I can give you a few examples:

Packages are not done well compared to linux. Brew is a poor replacement. It feels like the terminal and everything involved is constantly out of date.

The OS just has a lot of weird things, like the ribbon at the bottom taking up so much space. When I made is smaller and hidden except on mouse over it was incredibly rough.

Window management is decades behind windows or linux. It doesn't like maximizing windows and doesn't make partitioning screen space easy. I had to download a third party app to make it better, which was still worse than windows even in windows 7, and miles worse than linux with i3.

Mac has a lot of rough spots. I have two external monitors and occasionally after updates one monitor would be fuzzy or different resolutions, and it wouldn't go back until the next update.