No comment on Manaus yet.... telling :)
No vaccines are completely protective, they never will be. Even 75% effectivity (see: Delta variant) makes widespread transmission difficult.
If your threshold is complete protection then NOTHING will ever satisfy you.
Infection driven immunity falls on a wide spectrum. You cannot ensure a strong response, ad it's hard to test for adequate response from prior infection. Allowing mass infections is going to provide orders of magnitudes more replication events, variation, and selection (another fact you refuse to acknowledge) - and carries enormous cost to a population...
Yes it's possible that other viral epitopes are useful for driving immune response but the spike is by far the most antigenic and potent. The most important epitopes for immunity overlap with the important regions for receptor binding... making selection for increased potency but decreased neutralization very difficult.
You are taking all the exceptions and edge cases and making them the focus. There are many more exceptions and edge cases to infection driven immunity.
You do seem to have read some fringe blogs and can spam buzzwords though. One of the better trolls around here.