You're not wrong. It would certainly be interesting to see what kinds of antibodies everyone has but that's not feasible. There's more than one way to do it.
But you do sound like a crackpot with how many billions of dollars have gone into the research, and how few published reactions have occurred.
He is wrong. Vaccine immunity is usually stronger than natural immunity; that's what "adjuvants" are for.
For COVID, there's multiple vaccines, some of which include the spike and some include the whole thing. The most effective ones only include the spike, although of course that doesn't mean it's ideal.
But you do sound like a crackpot with how many billions of dollars have gone into the research, and how few published reactions have occurred.