Because it's just not that easy.
As Cern noted above, it really depends on the individual and a person who had a very effective response to the first two doses may have more antibodies at 6 months than someone who did not have as effective of a response at 2 months. The first person doesn't necessarily need a booster while the second one would.
Eventually time will catch up and anyone requiring a vaccination will not consider 2 shots a year ago to be fully vaccinated, just like anyone who requires a flu shot would not consider last years flu shot to count.
Back in 2020, when the virus first got to NJ, there were more people in the ICU because of just Covid than the total of all people in the ICU in NJ today. There were definitely valid capacity concerns because of Covid throughout the pandemic. Each state had to plan for and deal with their own surges at certain points, but the risks of capacity issues have since been mitigated because the far majority of adults have been vaccinated.