> The more times you had covid the less symptoms you are going to get isn't that so?

No, the opposite is true: the more times you get covid, the more damage it does to you and the more serious it becomes.

> ? When the immune system knows how to fight covid it's going to get better and better in response?

Not if covid damages the immune system, like HIV does.

> Just like natives in Latin America all died of diseases that wouldn't necessarily be fatal for Europeans because their immune system wasn't prepared.

This is not a good thing to compare to unless you want 90-95% of people to die.