This is exactly why voluntary individual action tends to be really ineffective at stuff like this, absent massive cultural support (e.g. consistent, widespread

This is exactly why voluntary individual action tends to be really ineffective at stuff like this, absent massive cultural support (e.g. consistent, widespread shaming and shunning those who defect). It's one of the main reasons government is, in fact, useful—it can be impossible to get out of these kinds of holes even when a large majority want to, without someone to make everybody play by the rules. The core problem is exactly what you noticed: that you can be personally paying, in relative terms, a large cost, while having no meaningful effect, and while others are choosing not to pay that cost and doing much better than you. When the world where you defect is functionally indistinguishable from the one in which you stick with it aside from that you'd be happier in the former, it's hard to justify continuing.