There have been numerous studies showing that 2 doses elicits higher antibody responses than natural immunity alone, here's an example of one:
> circulating antibody levels alone are not definitive measures of immune status
This is well established in the literature.
The paper you have cited absolutely does not support the claim that the "vaccine is more effective than antibodies from a previous infection".
Show me some real-world data of previously infected individuals getting severe reinfections at significantly higher rates than the fully vaccinated. That's the metric needed to make your claim and those data have not been produced. Also, the staying power of the vaccine is already in question BY ITS OWN MANUFACTURER just via the prospect of boosters. They admit implicitly that the immunity their drug produces does not last.