Isn't it in the terms of app stores that users need the ability to filter out abusive and bad faith users, and if the app developers don't comply, the stores need to remove the app? Muting doesn't cut it. I still see muted accounts in my feed. Blocking removes them entirely and I never have to suffer abusive accounts.
If that's true, this is only a problem with the implementation of muting. Muting itself is fine. Muting only hides tweets from the user and has no other side effects like "blocking".