I think the point people are trying to make is that general masking behavior has not been guided by rational consideration of where it is likely to be beneficial. So, it's a warning to slow down and think about it.
If we were talking about alcohol consumption "slow down and think about it" absolutely makes sense: I might be having fun in my 20s binge drinking but there are very real negative consequences of that behavior long term.
But in the scenario where someone is in their car with their mask on I'm missing the "slow down and think about it" rationale. (Again, I've heard the talking points on this, so I'm looking more for a real answer).
