Honestly the amount of crazy code involved in Linux font rendering[1], and then you get to CJKV support[2], it's mind-boggling. Even then, it's nowhere near as good as macOS :-/
Can you expand on that a little? I know a little bit about how Windows and macOS handle font rendering, but I know nothing about how Linux does things.
[1] https://gitlab.gnome.org/GNOME/pango & https://github.com/harfbuzz/harfbuzz
[2] https://www.amazon.co.uk/CJKV-Information-Processing-Ken-Lun...