if someone in the USA started manufacturing 5.8x42mm AR's, along with ammo, how successful would it be?

theres a cult following for 5.45; but for what its worth, 5.8 is theoretically better than both 5.56 & 5.45, so wouldn't that give it a leg up?
to try and even out the hypothetical, lets say it all costs the same as 5.56 rifles & ammo (nobody is gonna buy something expensive)

inb4 chinkshill
nigger, its a fucking cartridge that isn't even allowed for export out of china