[chrismorgan]

macOS mangles font rendering. They have this awfully-named preference called “font smoothing”, enabled by default, which actually enables glyph dilation, which is basically “ignore what the font author said, and make the font fatter than it should be”. This is the worst thing to happen since sliced bread or something. https://news.ycombinator.com/item?id=23553486 gives more details, including the biggest problem: people using overly light fonts because they use macOS that makes them bearable.

Quite apart from that, my understanding (as a non-user of macOS) is that macOS’s font rendering used to be better than it is now, because they used to do subpixel antialiasing but no longer do, preferring to simplify things because it’s not as valuable on high-resolution displays which they mostly (but not consistently) try to shunt people towards. Mind you, it’s still not useless on high-resolution displays, but definitely not as valuable.