There’s additional stipulations, the most crucial being the dictator thing.

The perception of a particular office-holder as a "dictator" is a very relative thing. Go look up the history of a few of our more notorious governors - Brigham Young, Huey Long, Frank Merriam, George Wallace, my own home state governor Greg Abbott - and how they flagrantly abused their powers to impose their whims on their constituents. Depending on which side of the fight you're on, the label of "dictator" sticks firmly or slides right off.

You've also got your Lincoln and FDR types - folks who absolutely were "dictators" from a legalistic perspective, but were vital to the continuation of the nation as a whole.

The thing about dictators is that they're often very popular. Sometimes even popular for good reasons. So even without a FPTP system, a guy taking 50%+ of the base vote because the constituency wants a strong man with a plan in high office is going to get what they asked for.

it would be easier for the US to adopt ranked choice voting

It would be functionally impossible to adopt ranked choice voting, as this would require a supermajority in the legislature (who all won their seats FPTP) to approve it or a Constitutional Convention (a thing that has never happened in our 235 year history) to be called by a supermajority of state legislatures (who also all won their seats FPTP) to change the system by which they secured their seats in a manner you believe would put those seats at risk.

All this to get a system that will still produce dictators any time a right-wing media blitz shifts popular opinion too far in Trump's direction.