Zed developers themselves acknowledge the blurry font issue [1], so either you just don't notice blurry fonts or 1920x1200 on a small laptop screen is HiDPI-enough to kinda hide the blurriness.

My desktop monitor is 1920x1080. On my computer and display; Vim, Emacs and VSCode are all able to render their fonts crisply while Zed is a blurry mess.

[1]: https://github.com/zed-industries/zed/issues/7992