Name a system that doesn't enrich a small group of people when actually implemented in real life. So yeah you pick the least bad of the options you have.
edit: That also includes being stable against competing systems. A utopia that is conquered in 5 minutes and replaced with a dystopia is not a utopia.
Imo let's be real, drop the pretension. I'd rather we get off the notion that these things are possible. I.e. we are ruled by smart people (aristocracy), that enrich themselves, but that are smart and have skin in the game. Rather than dumb (and impressionable) collective deciding in a popularity contest, probably _extremely_ influenced by a 3rd party (media), pretending it's fulfilling its duty, while it's actually falling in some 'cool' 'wolf's' song, that only accomplishes short term gains, while mortgaging our future.
Just drop the pretension.
Edit: maybe I'm schizo-ranting, but in my opinion, this is a very sober/hyperconscious perspective, that should be had by everyone. Not this Plato's Cave bs, that we live in a 'free democracy' where nobody questions status quo, except a minority of right-left non-npc people.
edit: That also includes being stable against competing systems. A utopia that is conquered in 5 minutes and replaced with a dystopia is not a utopia.