I have a 32” 4k monitor and on macOS fonts are blurry. Readable, but notably worse than on linux with X and the basic hiDPI settings from ArchWiki (with fractional scaling in both cases).
I can highly recommend the LG UltraFine 5K in case you're looking. I've been using it for years, and it's been a dream.
https://www.bhphotovideo.com/c/product/1499337-REG/lg_27md5k...