Hard to predict as many of us have not gotten there. I'm at 50K and 43K on the tweo crossies I own.

That said, Benzes do have a record of failures in the high mileage range. In order of failure by my experience.......
Cruise Control
Power window regulators
Dash may crack ( don't use STP on it)
The heat controls
Radios and electronics.
Ancillary toys like the wing would fall in this area.

A lot of our Crossie is plastic inside. I would worry about that stuff.

It is a Benz so such amenities are cool but expensive to fix at the Dealer. That's why you have the Forum.

Engine, drive train, suspension are all overbuilt. So unless the car is seriously modded or driven very hard, they should last to 200K no worries.