It’s just a driving assistant, like in any other car. As far as I know, currently Mercedes is the only one who implemented autonomous driving, and even that one is limited to some specific areas. But at least that one is real. So much, that legally Mercedes (the company) is considered to be the driver of such cars, in case anything happens on the roads.
Depends on your definition for autonomous driving which mainly depends on your ODD but they’re not the only ones. Honda ,Volvo and GM have something. Others (i.e. BMW) have stuff next year but they’re all going with more accurate names. CoPilot, PilotAssist, Super cruise, Traffic Jam Pilot. Makes it clear that these are drive assists, not drive replace.
Mercedes has Level 3 autonomy in certain highway situations, so you are legally allowed to watch a video or read a newspaper. You just need to be able to take over again within 20 seconds or so.
Others are following close up, I think Audi had to postpone Level 3 a bit etc. BMW has something in the pipeline as well.
But these are really more than drive assists. I really find the “Level n” specifications more helpful than “drive assist” vs “autonomy”
None of the other brands oversell what they are offering.