Liability.

Not sure how that relates to the point OP was making. Unless I misunderstood his point?

> Mercedes is delivering a product that only support a few features but do it well

This naturally implies that Tesla experimented with a broader set of self-driving features in an throw-it-at-the-wall experimental fashion. Which is more of a technical/product management question than a financial/legal/marketing one. Unless OP simply means Mercedes released the same set of features just extremely restricted in what you can do with them?

If so the hacker/experimental vs limited focus on "small set of features" dichotomy is not super relevant. It's just business risk aversion or gov regulatory strategy, not product/technology development strategy.