The survivorship bias is strong in you.

You're ignoring unsuccessful mutations... But those are the chaos monkeys that really matter!! "on the order of 10¹⁷–10¹⁹ individual nucleotide mutations per month". In part because infectious virions are far fewer than total viral RNA copies.

Which ends up with 2-3 mutations per month in the successful lineage. That's the "rare" number you're thinking of, but mutations are extremely common (as anyone with cancer finds out).

Your "energy" point is just plain wrong. You might carry 100ug of virus when infected - a tiny proportion of your weight. Total mass of virions in humanity at peak might have been 10kg.

See "The total number and mass of SARS-CoV-2 virions" https://pmc.ncbi.nlm.nih.gov/articles/PMC7685332/