> Unless you are running some really complicated globally distributed backend your roundtrip will always be higher than 80ms for all users outside your immediate geographical area.

Many of us don't have to worry about this. My entire country is within 25ms RTT of an in-country server. I can include a dozen more countries within an 80ms RTT. Lots of businesses focus just on their country and that's profitable enough, so for them they never have to think about higher RTTs.