Tasha’s Cauldron of Everything, page 141 says the following (emphasis mine):
Common in-game limits include - but are not limited to - [...]
Common out-of-game limits include unwanted physical contact, dice-sharing, dice-throwing, shouting, vulgarity, [...].
All of these make sense to me, except for dice sharing. What are the objective issues to dice sharing? Why would people find dice sharing offensive? What about it would be offensive? Would it be forcing a player to use your dice, or forcing a player to share their dice? Or would it just be someone would be offended by you sharing your dice with someone?