When you add up all the 'underlying' conditions that covid can aggravate and kill you via it adds up to more than 50% of the population, and once you are over 60 that figure is probably 90%+. So your extremely healthy part of the population is a minority group (who BTW can still get severely sick and die of covid, just in lessor amounts). Most of us writing here probably have underlying conditions of some sort, some may be aware, others not until it sends them to hospital or kills them.