This has stopped working many years ago. Every top-level domain now has its own private cache of all other domains.

You likely have dozens of copies of Google Fonts, each in a separate silo, with absolutely zero reuse between websites.

This is because a global cache use to work like a cookie, and has been used for tracking.

Where "many years ago" is... 11 years ago for Safari! https://bugs.webkit.org/show_bug.cgi?id=110269

ah, I had forgotten about that, you're right.

well at least you don't have to download it more than once for the site, but first impressions matter yeah

No, because of cache partitioning, which has been a thing for a while.

https://developer.chrome.com/blog/http-cache-partitioning