Yup, there’s no universal definition, but whatever country you’re pursuing a sit in, they’d use that country’s range, not another country’s.
And if a host can’t tell you what they’re getting, then you’d have to help them figure that out — guide them through speed testing, at the very least. That itself has accompanying downsides, as I’ve mentioned.
No matter what’s typically available speed wise in each country, people who don’t know how to speed test on their own would be unlikely to have paid for high speeds — that’s because people who want high speeds tend to have chosen that intentionally.
It would be unusual for someone who didn’t value high speeds to unknowingly have landed with a high-speed package, because they’re always more expensive.