I'm not a developer, so I cannot give a technical answer to any possible barriers here.
However, the issue has been raised on the Mastodon github at:
https://github.com/mastodon/mastodon/issues/23034
The thread goes into more detail about the technical possibilities/drawbacks.
If you are comfortable using github, you can vote to request this feature by giving a thumbs up to the first post in the thread.