Being a lawmaker in the current capitalist society doesn’t make you the ruler (see lobbying). I’d say the few that rule are those with large amount of capital and influence, so oligarch is well applied here

Edit: also one of the perks for rulers on the worse regimes (authoritarian regimes, monarchies) is that law is not the same for the few that tule than for the rest, law is definitely not the same from the point of view of this wealth maxers