>This is also why people 70+ are almost fully vaccinated in the US. For that age range it’s an extremely serious disease with a high chance of killing them after infection.

Older people certainly dominate the vulnerable groups, but there are many other people living with various forms of immune system dysfunction. This is why the rest of us need to mask, vaccinate, and get boosters to minimize our chance of propagating the disease to the more vulnerable parts of our population. Not doing so is basically saying you don't care about other people.