It is not a party trick. It literally allows you to do anything while stuck in traffic, which is definitely not a rare occurrence. Meanwhile Tesla's FSD beta doesn't allow me anything I can't do with another car, as I still need to pay the same amount of attention and hold the same liability. Mercedes could offer a similar service, but won't as their assistants already offer a similar experience without the dangers of Tesla's FSD.
You've got that exactly backwards buddy. Tesla could easily offer the same thing, but why would they waste time with that BS? Mercedes 100% cannot offer full self driving on any street. What world are you living in?