> it's true of specific things, not specific epochs

It's true of all epochs. If it isn't in the indivdual interest of most people in a society to continue participating it, at a certain point, they don't.

> If all the government did was collect 5% in taxes from everyone and use the money to prosecute murders and maintain bridges then the result would be a huge net positive

Most people obviously disagree. And for obvious reason. If you're my neighbouring sovereign doing this shtick, I can invade and extract a premium.