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.

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

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