No, the picture is quite complex. An increasing proportion of people are vaccinated, and vulnerable people who are more likely to have severe COVID outcomes tend to be less reckless and are proportionately more likely to be vaccinated; while unvaccinated people are increasingly likely to have been infected already and (if they didn’t die) now have some immunity.
Go to Figure 3 in this piece and toggle between Sep 21 and Aug 22. It goes markedly from
Sep 21 - mainly unvaccinated people dying, all ages Aug 22 - mainly elderly people dying, regardless of vax status
SARS-CoV-2 has not “…killed most of the elderly/immunocompromised people off already,” (a fact that can be assessed just by looking at demographics) and suggesting that to be the case is often taken as rationale for why there is no longer an epidemic and why we should be taking public health measures to track and limit outbreaks to protect vulnerable people. We should be encouraging periodic vaccination across the population to limit both gross deaths and proliferation of mutant variants with immune escape. Unfortunately, certain political figures have made the point of reinforcing anti-vaccination sentiment to the point of flagrantly lying about vaccine efficacy, which should be regarded as willful negligence in public leadership.
I think your intuition was a fair representation of what was happening in late 2021. At that point, there were more people who were vulnerable because they were unvaccinated than people who were vulnerable because were old.
Since then, a lot more people have gained immunity either through vaccination or surviving infection, so we have transitioned into mostly old and vulnerable people dying, regardless of vax status.
But the unvaccinated are still overrepresented. It is still quite definitely true that after you control for other factors, you are much less likely to die if you are vaccinated.
An interesting corrollary to all this is how much the unvaccinated, by acting as particularly virulent carriers, are contributing to infecting the weak, and thereby killing the unlucky / extra weak among them.
Although, it would be interesting to see how many of the dying people have had their updated boosters. Only 40% of those 65 and older have had the bivalent booster as of today according to the NYTimes. A few months ago, this number was much lower. We already know that vaccine efficacy wanes faster with age or lowered immune status.
My grasp of statistics is very shallow. And I don’t have the stats on how the population of 50 to 64 yr olds is to the population over 85 but the CDC list of deaths in the 50+ category is 11.3% of all deaths in that population is from COVID vs 85+ 9% of deaths are from Covid. That chart does not give a number for excess deaths over prior years or over pre covid. But age does not seem to be protective (except for kids up to 30) COVID-19 Provisional Counts - Weekly Updates by Select Demographic and Geographic Characteristics