Exactly what did they sell out? Exactly what technology did China "steal" from Mercedes?
Car manufacturing has been a global business for more than half a century. Should they just ignore a major emerging market?

To get a car certified to be sold in China, you need to get a certification, where you need to provide all technical plans and documents for them to be certified. Most of the time a year later there would be a quite similar looking car from a Chinese brand. Collected data about the car and customer is stored on Chinese servers, where the government has access to.

So I am pretty sure they would never give any of that data to their own manufacturing companies...

Of course they should sell their cars there, but they should have also prepared for what will happen in the long term. They kept selling petrol cars, because they were are the most profitable cars.

Yes the Chip shortage had the effect that car prices increased, making each car more profitable to sell.
But the after effect was a near recession and inflation where profits and sales fell back. Only helped partially and regionally subsidizing EV sales.

Their sales of petrol cars gone down in China the last few years and this is where they make the most profits.

Doesn't change the fact that Mercedes today make the best electric cars on the market without comparison. So they must have done a heck of a lot more than just laughing.

If they make the best cars, why no one wants them? The sales figures don't show it. Teslas are expensive still sell a lot higher volume.

Don't get me wrong, I would hope they do better, as I hate Musk and his Swasticars. I am from Germany and would like our economy doing well, but they should take their fair share, why we are in this situation today.

The management of the German car makers made a bunch of bad decisions and now the employees have to take the burden.

For example an S-class brings about 8000€ of profits, EVs are no way near that. And they sold most of their most profitable cars in China. Now this has gone back a lot and they are missing this income.