macOS out of the box fucking sucks for monitor scaling with third party monitors. It's honestly laughable for a modern OS. You can install some third party software that fixes it completely, but it really shouldn't be necessary. I use an (admittedly pretty strange) LG DualUp monitor as a secondary, and out of the box macOS can only make everything either extremely tiny, extremely large, or blurry.
Other than that, I've had no problems at all, and the window scaling between different DPI monitors is a lot smoother than it was with Windows previously.
For me it's that compared to windows and linux, handling multiple windows between screens is always problematic, and is made worse by alt-tab bringing up all the windows for an application, which means they pop up in the other monitors too which isn't usually what I want. Maximizing is usually not as straightforward as one would hope, and the dock moves to any window if you leave your pointer at the bottom which can get annoying fast. As some point out apparently there's 3rd party software that allows you to fix these issues, but that's not an option for me because I use a locked-down Mac for work and can't install 3rd party software, so I'm stuck with the annoying base behavior.