Regardless, I do like polygon for its cheap fees (today); it is practically better than eth in most ways. However, it is just an eth side chain, and the whole “don’t need to commit tx for all eternity for all every purchases” applies here.
I don’t believe it is possible to scale this anywhere where it needs to be. For this, we need Lightning network style constructions.
Lightning is promising. The first tether transaction on lightning was only a month ago, however [1]. So that's not yet a boring enough solution.
Ethereum and Polygon won't (today) scale worldwide, but if we're able to gain traction we'll (a) branch out to every other network if necessary (b) contribute to networks so they can start to get to global scale
[1] https://bitcoinmagazine.com/technical/tether-sent-using-the-...