By that logic, should speed limits be ditched, because it should be left to individual concerns about accidents?

I can lower my risk of catching Covid by wearing a mask, but the risk drops a lot more if the other person is also masking.

And to make a reasonable judgement about your personal risk factors, I assume you read all the latest Covid research and evaluate it, before then assessing every person you come into contact with in case they're immuno-suppressed or immuno-compromised, etc?