I'm far from the most hygienic person, at least according to most social norms. But people who lick their fingers while eating seem to be on a whole new level of degeneracy. Like, what possible reason could you have for doing that? You're going to swallow a fingerfull of bacteria, skin cells, and oil just to get an extra drop of your mayonnaise?
Is it a cost saving thing to get the most out of your jar of sauce? Or do you just love the sauce so much that you're willing to engage in socially tabboo and disgusting behaviour to show affection to it?
Here's an idea - let the food drip on your plate, then lick your plate when you're done. I think it's telling how clouted in judgement our society is that this would be considered awkward but licking your fingers, even post-covid, is widely acceptable.
I hereby request anyone who does this to stop and be normal.