The efficient frontier is large, but a lot of the things we do are just dead-weight losses. There are cases of incompatible values where we have to make trade-offs, sure, but there are also cases where we're being irrational under any value system.
> but there are also cases where we're being irrational under any value system
I think the set of possible value systems is much larger than you appreciate. For example, nuclear war is perfectly rational when your value system is "KILL ALL HUMANS".