This is entirely because so many people block Space Karen, isn’t it?
It's really easy to get around the block, so I would have to agree that it is not that useful of a feature.
Blocking is useless if your profile is not private.
Have people been blocking Musk?
[dupe]
Others have mentioned, it is in the terms of the apple App Store and google play store that to have your social media app listed, it must support blocking(1)
[1] https://developer.apple.com/app-store/review/guidelines/#use...