Why Harvard?

I'll be applying to university in Ireland, the UK, and to a few US Ivy Leagues and assessing my potential options and I'm left wondering why Harvard has the most international name recognition of any university. I have always heard about it but never figured out what they were actually good at academically besides producing billionaires and world leaders.

In Ireland everyone knows Oxford because it is the best university in the UK and the oldest in the English-speaking world. Many people know Cambridge because it is affiliated with Oxford, similar to how many people know Yale because it is affiliated with Harvard.

But I am left wondering why exactly Harvard, according to any metric or anecdotal evidence, is the most known university in the world, or at least the world I have been exposed to, which is primarily the West and Asia. I know that in certain parts of the former British Empire like Pakistan and Kenya, Oxford tends to be the most known university, but these are few and far between compared to the rest of the world where Harvard has more recognition generally. Is it just because it's the oldest American university or is there something Harvard did that made it a lot more famous than its peers?

I have no skin in this game by the way because I'm not even applying but I was just wondering.