In any well designed online game (please don't use shitty ones against me), cheaters aren't able to hijack the entire system or ruin an economy. Their exploits break the game temporarily and most of the time it doesn't affect that many people. In bad cases, the state gets rolled back, the exploit patched, and the game continues. Sometimes things are just unavoidable, and everyone counts their losses.
I think blockchain has the potential to make fairer and more resilient systems, and with new incentives as well. We can use game theory to try wildly different societal structures, and quickly switch to another one if one doesn't work well.
On some level, trust always has to be present. If we make the rules trustless, enforcement becomes the bottleneck (until Robocop?), but it's still potentially better than what we have now where we simply have to trust millions of other people not to fuck with anything too much.
Or people think to themselves "well, the papers are authentic but the meaning is open to interpretation" or "well, it's not such a bad thing" or "well, but the others are doing worse", or a myriad of things. All of those are real arguments I've seen made.
It is naive to think that you can codify everything into a system in a way where there's no open interpretation possible. It is naive to think that people will trust the system instead of what they heard the system says, or that people will trust the system over leaders, or the the people responsible for enforcing the system decisions and feeding the system information won't find a way to elude responsibility.
In general, it is naive to think that the problem of corruption, which is a problem about trust (if the person I like says he didn't do it or did it for a good reason, then I trust him above all else), enforcement (the ones responsible for enforcing the rules are the ones breaking them) and tolerance (people don't care that much about corruption if it doesn't harm them) will be fixed by a solution that at most will help a little bit in the enforcement part.