You’re right in the sense that people often use the term imprecisely and hyperbolically, but in this discussion they are more right than wrong, at least by this measure: https://en.wikipedia.org/wiki/Oligarchy#Putative_oligarchies

> That’s entirely different than determining agricultural policy, or putting people in jail, or conducting the census, or maintaining the border, or doing anything else that a ruler does

You’re making a mistake of your own by conflating oligarchy with tyranny. They often go hand in hand, with the former generally preceding the latter. So it’s probably better to cry oligarchy before it’s a given rather than afterwards.

A better term for what people are trying to articulate is plutocracy.

The poorest 70–90% of Americans effectively have no representation – there is almost no correlation between their policy preferences and the voting record of their representatives.

On the other hand, enacted policy aligns quite well with the interests of large corporations, and I'm not aware of any causal explanation besides the obvious one.

If Elon steers Tesla and SpaceX, he is indirectly steering congress (or at least has his hand on the wheel).

That's still a far cry away from an oligarch.

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

Why would you lobby someone who doesn’t rule?

I’m still waiting for examples of how Musk has exercised his sovereign power.