You are very much mistaken.
It has always been known that SARS-COV-2 and other comparable viruses demonstrate antigenic drift (I'll state again this is why so many resources were pumped into sequencing, tracking and predicting genomic changes), and therefore that vaccine effectiveness would reduce as the virus accumulated mutations.
It is also the very basis of epi 101 that a efficacy is in a trial will not translate to real world effectiveness, and this is something I'd expect undergrads to be aware of.
There's also been transparent reporting on estimating vaccine effectiveness & how much it has dropped in regards to various variants (for all the vaccines - although you seem very fixated on Pfizer), which is why I'm confused about your focus on early trial results which are no longer relevant to the current situation.
This is why, as has been said many times, countries worldwide are moving to an annual booster programme which will use an updated vaccine each year, just as we do for comparable viruses such as 'flu.
You may not be in a demographic offered this booster, and of course you can just turn it down, but it would best to make an informed decision, which it seems you are possibly not.