> People who trust each other can cooperate together without expending resources on protecting themselves.
This is not how security works. You need to consider the adversarial case, not the average case.
> Consider Bitcoin - the cost of that trustless system that barely works is mind-boggling waste of electricity
The "waste" is actually for the purpose of putting a floor on the cost to trick someone into believing a non-consensus history.
Consider Bitcoin - the cost of that trustless system that barely works is mind-boggling waste of electricity. Or look at layers and layers of bureaucracy people create; a lot of it exists to mitigate the problems of lack of trust by creating a system that doesn't depend on actors to be benevolent.
It's true that systems based on trust are fragile - malicious actors can abuse them, and if there are enough of them, the public trust will collapse and the system will go to hell. But that's only an argument for why should we fight for ensuring trust. Why we should punish defectors - the liars, the cheaters, the abusers. Because we need this to be efficient.