Yes, but the question is how long that immunity lasts for.

Not all diseases provide immunity forever.

> Every disease in history has conferred immunity except for HIV, which is chronic.

This is not true, nor a generally good guideline to think about things. Coronaviruses generally confer short immunity periods.

> 2) What is your alternative? The US lost to mother nature.

In the very least, being aware that long term herd immunity is not a viable goal.

You're right, every disease we catch gives us complete immunity. That's why when you catch the flu once, you're immune to it forever.

I'm being sardonic here because you have a severe misunderstanding of how immunity and our immune system actually works. Some diseases (like the chicken pox) we never truly beat, it just becomes latent. Other diseases we only become briefly immune.