It could be a small factor but I’m not seeing a direct correlation.
Florida has the largest elderly population (20% over 65) but is 19th in Covid deaths per capita (344 per 100,000).
Utah has the smallest elderly population (11% over 65) but is 47th in death rate (148 per 100,000).
Mississippi has the highest Covid death rate (418 per 100,000) but is 31st oldest (15% over 65).
Hawaii has the lowest Covid death rate (100 per 100,000) but is 8th oldest (18%).
Looking at various factors the ones that jump out are poverty rates and obesity rates. The 5 worst death rates (Mississippi, Arizona, Oklahoma, Alabama, and Tennessee) are all high on the percent living in poverty list (Mississippi 1st, Arizona 14th) and high on the obesity list (4 of the worst 7, Arizona being the exception at 30th), compare that to the 5 best death rates (Hawaii, Vermont, Utah, Washington, and Maine) and they are low (Utah 49th, Maine 30th) on the % poverty list and low on the obesity list (4 of the best 12, Maine being the exception at 28th).
Poverty seems to be the biggest factor, likely because it leads to worse overall health, but even though there’s some evidence they are bigger factors they’re still not a direct correlation. Too many factors at work to pinpoint one or two alone.