You're saying "If you survive getting covid without serious injuries once, then you'll be less likely to get serious injuries on a re-infection later". The vaccine is to make it less likely that you get serious injuries from that first exposure.
Please read the context of what you're responding to.
COVID was around before the vaccines, and before the boosters, and between the boosters. Some of us got it before the boosters were available, and before the next booster was due. This is the context you're responding to.
For a stupid real world example, my college friend had COVID was required to get the booster while he was recovering from COVID, so that he could continue school after. There's plenty of nonsense still going around. Natural infection usually doesn't count in the school system, from what I've seen. Surprisingly it does, where I work.
Are there any people left that haven't had their first exposure?
The argument makes more sense when you take into account that the interesting case is actually "given that you've already had covid, should you get vaccinated?" rather than "given no exposures yet, should I make out with someone that has it or should I get vaccinated". I've seen a lot of noise about the latter case, and a lot of overlooking the former.
You're saying "If you survive getting covid without serious injuries once, then you'll be less likely to get serious injuries on a re-infection later". The vaccine is to make it less likely that you get serious injuries from that first exposure.