On the one hand, you're right about using a brand name as shorthand for what that represents. But you're missing a point that's true of the startup metaphor bu

On the one hand, you're right about using a brand name as shorthand for what that represents. But you're missing a point that's true of the startup metaphor but not of the mercedes one: "uber for x" has been absolutely beaten to death as a low-effort startup pitch, to the point of being a useful counter-signal. Mercedes has no such baggage when it comes to judging the people saying the word.