In my experience it's a little hit and miss with macOS. You need a monitor that is specifically listed as being supported by macOS. If not you get rather strange results. I had a Dell monitor that, under macOS only, would sometimes freak out and flicker if you had to many electron apps open.

In some sense it's reasonable that you need a supported monitor, it's just strange that Linux can support all these monitors, but macOS can't?

Adjust it to what? Making a 4K monitor look like 1440p (or a non-1080p or 4K desktop) ends up with a non-integer scale on macOS AFAIK. They also completely tore out subpixel font rendering for low DPI displays.