In this particular issue, MS has an opposite problem: you grab a document link, grant a permission to someone, and they still can't access the document through the original link (you need to fetch a new link just for them).
Kind of. The default behavior is to create a new link. So when you grant someone access you are actually creating a new link. However, you can find the buried manage access settings and change the permissions on the original link. If you do that then they can use the original link.
(Teams makes this Byzantine in the extreme to accomplish as you have to go find the folder it drops all shared files in to gain access to manage access settings. But it does allow you to retro change access even for things shared in Teams)
Yeah, many things are definitely possible but to me it seems like the user experience is driven by the technical implementation and architecture, instead of vice versa.
From the outside looking in, it's the age old organizational problem when there are no good synergies between customer experience and development teams.
(Teams makes this Byzantine in the extreme to accomplish as you have to go find the folder it drops all shared files in to gain access to manage access settings. But it does allow you to retro change access even for things shared in Teams)