It's actively being worked on - there have been 8 font rendering PRs in the past 3 weeks, most recently yesterday: https://github.com/zed-industries/zed/pulls?q=is%3Apr+is%3Ac...

A downside that comes with the territory of building the rendering pipeline from scratch is needing to work through the long tail of complex and tradeoff-heavy font rendering issues on different displays, operating systems, drivers, etc.

I know it's taking awhile to get through, but I agree it's important!