Idk sorry but I think the idea of humans as basically infallible and capable of rationalising all their decisions if they simply "think" about it belongs to libertarian economics and socialists shouldn't engage in it

Humans are fallible. The only thing we've managed to establish about human nature in all their history is in fact that they Do Some Shit. Socialists should propose ways to organise society that are stupidity-proof rather than metaphysical culture shifts.

Instead of trying to convince people to be less selfish, how about we build societies and responses to societal problems that are simply resistant to any damage that could be caused by selfishness?

That, to me, is the necessary key question of any preparation for future crises such as more pandemics. How do we prepare our society to withstand shocks to it in future even if compliance and trust in government is low? "We can't" is not a good or acceptable answer.

All government contingency planning for future crisis must have a worst case scenario where compliance is idiotically and upsettingly low.