Honestly this is the best way to proceed. No one from other teams is beating down Valterri's door. And F1 pays well plus he's set himself up in quite a few other businesses such as merchandise, coffee, vodka and others.
If he stays at Dauber it's a safe seat, he's beating his teammate and he can look forward to further good pay.
Plus, if Audi comes in strong he may find himself in a title contending car.
Chinese customers are not interested in overpriced German cars. Their regional suppliers offer design copies for way less. Volkswagen has dropped prices so much, that the same car in Europe costs like 30% more. Helps that they build them in china too. Audi Motorsport, or Quattro as a brand is in no man’s land in china anyway. Bottas driving a shitbox. If you’d put Zhou in the second Red Bull he would perform like every other race driver in that seat, bar his mental health limiting his confidence. These drivers are within margin the same but limited to their teams, machinery and confidence.
You're making a case for why making them interested in overpriced cars is a good idea. F1 is advertising and that's never about explaining what people need but what they think they need.