Because people will delete and create new modes as they iterate so those hash links become stale. So while the person who replied to you is technically correct, effectively it is still very unstable.
Similarly, on pages like GitLab you can link to specific line(s) of code in a file...but it often is the head of that branch. The URL will resolve in the future, but its pretty common that the chunk of code has moved.
I wish it was easy to grab a URL for that specific version, with a banner at the top saying it's not the newest version of the code (something I sometimes see with documentation). I don't see why Figma couldn't do this, too.
> Similarly, on pages like GitLab you can link to specific line(s) of code in a file...but it often is the head of that branch. The URL will resolve in the future, but its pretty common that the chunk of code has moved.
On GitHub you can hit the 'y' key[1] and it will add the revision into the URL.