I don't understand who your "they" is. In my opinion there were valid reasons for both decisions on antibodies and boosters. Since I know one of the people in your linked podcast, I will not comment on it.
No that's simply wrong. Antibodies are relatively unimportant and levels decline quickly. What actually matters far more is cellular immunity. Fortunately the vaccines and recovery from infection have both been shown to produce a significant level of durable cellular immunity in the vast majority of patients.
Who do you personally know in the linked podcast? What are your medical qualifications?
https://peterattiamd.com/covid-19-current-state-omicron/