Remember... and this is the pharmaceutical companies' and governments' own data:
The original vaccines provided 70% protection against the original strains (and the alpha strain of last winter), and 95% with two doses. By the time of Omicron, it had diminished to 35% with two doses.
The third dose only restored it to 70% protection—meaning it only reduces the chance of infection by half compared to two doses.
So the original series was 95%, but that dropped to 50% with the next shot. You're seeing that fatigue play out already.
In contrast, the polio shot was 90% after two shots, and over 99% with three, with the last one administered years after the other two. That protection endures to the present day.
There are no two ways around this: we are dealing with a failing vaccine.