Restaurants aren't fighting regular folks to make food supplies scarce and jack up food prices. You can choose to not go to a restaurant and that won't affect your grocery bill. They don't privatize food, they offer an actual, non-essential service which is to cook it for you, which deserves compensation. A restaurant organized as a worker coop is ethical.

OTOH, parasitic landlords are responsible for the scarcity/prices of housing. If you don't rent their appartments, you're still affected by their greed because the prices are high because of them.

It doesn't compare at all.