Perhaps instead I might be following Covid guidelines for the following reasons: so I don't pass the infection onto those who are indeed vulnerable; so I don't overtax an already overtaxed healthcare system and healthcare workers. Part of the ineffable human spirit, IMHO, is altruism: which in this case can manifest as taking on a set of mild day to day inconveniences in order to help others be happier and safer. I do believe altruism is a (not exclusively) human characteristic, which means that part of 'joie de vive', alongside wine, piano playing, etc., is knowing one is doing something for others.
Honestly, I don't think it's as extreme as "if coronavirus were ten times more fatal" that would lead us to naturally take on mitigations. Instead, it would be if the death rate were evenly spread across age groups. Then, the motivation for avoiding some piano playing would be the immediate cost to self or close friends, rather than the abstract cost to some other group.
All that said I am quite sympathetic to the motivation behind your argument, but I believe you and GP are ignoring some motivations people might have for following or being 'bureaucratic automatons'.