That's true. Which is why restaurants in tourist spots should be less trusted. But most other restaurants have enough returning customers, and the customers have enough knowledge about the product they're buying, that the feedback loop (good product -> more profit) is much more direct.

That ignores the issue - being hungry is a basic need and it's ok that we keep getting hungry and meeting that need through restaurants.

People getting sick is not a basic need unless you are a healthcare company. That's why the incentives are conflicting.

Getting hungry happens naturally, so does getting sick. Restaurants and healthcare companies are needed to address each need. The incentives are the same.

Absolutely false.

Getting hungry again happens naturally regardless of the choice of food offered by a restaurant.

Whether you remain sick, are cured, or get sick again depends significantly on the choice of treatment offered. Healthcare companies have an incentive to choose treatments that don't cure you.