With Covid as a prompt, but not only because of Covid, it is worth thinking about the economics of sick leave more seriously. How about this for a purely private solution for face-to-face workplaces?
Give each full-time worker three sick days each year. It is not only “paid” sick leave, rather you are paid an extra bonus to take those days. That way you do not bring a cold into the office. On net, it now becomes more than culturally acceptable to plead sickness. Most people will be doing it, and without shame.
Other components of the wage package can adjust to keep the net real wage constant.
Some very hardy individuals still won’t take any sick days at all, and many of them will love working. In fact they should be “taxed” somewhat more, since their intangible benefits from working are so high.
If some individuals allocate their sick days to days when they are actually sick, workplace transmission of illness will decline, to the benefit of productivity. And a general norm is set that may make it easier to deal with the next pandemic.