IMO … Your comment is a nonsense. Or I misunderstood your intent.
The vaccine reduces severity of infection and prevents many potential infections from gaining a foothold sufficient to be symptomatic. The measure of merit is not “prevents anyone from ever getting COVID”; it’s “Prevents most people most times from getting COVID and prevents nearly all cases of severe COVID.”
More vaccine does not produce more immunity. At least not beyond a certain threshold. If your immune system has the ability to remain hypervigilant against COVID for e.g. 6 months, then is merely vigilant thereafter, then there is benefit to vaxxing every 6 months, but no further benefit to vaxing every 3 months, every 3 weeks, or every 3 days.
COVID is now part of the human experience. Akin to flu in that regard. Substantially everyone, vaxxed or otherwise, will have a mild case now and again in their life. That does not equate to “truly no hope” by any reasonable definition of those terms.