Benz makes over 50 distinct models, BMW over 40. Tesla has 2 or 3 models and can focus all its attention and expenses on one big thing. It's a classic fast-moving competitor upsetting the dinosaur uber-brands with their huge legacy factories and market base.
It baffles me how German manufacturers continue to put more and more models on the market each year. VW for example is actively offering more than 30 different base models right now, each with 4-6 additional variations. Plus new updates and revisions every year or so. How many choices does a consumer really need?
It seems impossible to hit a top price–performance ratio with so much overhead.
There is not much additional overhead to those extra models. Each manufacturer has only a handful of basic platforms and drive trains. They can come up with a new model by just combining existing components and doing a little further customization. So it's worth doing if it allows them to capture some marginal additional sales.
Sure, that's the traditional analysis, but I think some companies (Apple) are showing that a simpler product line can lead to more sales. Customers are less likely to buy if they have too many options in some cases.
You're talking about extremely successful global companies - perhaps catering to the needs of their customers is something that sells more vehicles.
At least the major German manufacturers regally outsell the competition in EU because they actually let people choose what kind of car and equipment suits them. Being shoved down a few lanes Apple style is a common complaint for Asian manufacturers here ("Want that active cruise control? Tough luck, it's +8000EUR and you MUST get leather seats and bunch of other crap as well!" type deals).
Car manufacturers have tried that. It doesn't work, at least not at the high end of the market. There's always another competitor willing to eat your lunch by giving customers something closer to what they actually want. Their products are 1 – 3 orders of magnitude more expensive than Apple's so the market operates in a totally different way.
You can all other manufacturers and in the end, you have the choice between a metallic grey car and a metallic grey car. Or, for the last 2 or 3 years, a white car or a black car. With the same shapes. Yippee! Variety, originality, Hosanna!
[Source: https://roadster.com/Mercedes-Benz and https://roadster.com/BMW]