> I never understand why people make comments like this
It's intentional, because the location has nothing to do with the actual point. Stating it invites people to focus on the location too much instead of the actual point, or to say things like "oh that's just your country / town, we can assume that's anomalous".
Which would be missing the point entirely.
If you're interested in the location you can find out. It's no secret, though I would advise against trusting people's locations on LinkedIn, they are often not where the person currently works or lives.
But I'm not interested in stating it. For the point I was making, the specific location, or even the country, detracts from that.
You've traveled in 50+ countries. Just from that, you're an extreme economic and social outlier. You are almost certainly taking journeys that are systematically different from those taken by the majority of people, and the price brackets and journey routes you're comparing between services are different than those used by other people. It may well be that the comparison works out differently as a result.
Not to disregard your experience. You've plenty. But you are very unusual, and it's impossible to travel that much without taking journeys that other people never or very rarely take.
I would not be surprised if the "obvious foreigner" premium is there for taxis, even if you're experienced. I'd find it unlikely that you became so intimately familiar with all 50+ countries as to get the true "favour for a friend" fare in all 50+ including those where that's more common, and that you took the same journeys as locals do in all of them.
On the other side (and on the original topic), Uber has reason to optimise for traveller cohorts. If Uber wanted to seem cheaper than local taxis to people in your cohort, to a greater extent than for other people, they could probably do that, and it would make economic sense if their algorithm statistically optimises for that. Profit-maximising algorithms with "personalised" pricing default-optimise for trade with wealthier customers who use their services more often, for journeys associated with other spending, such as to/from travel hubs and hotels, and for separating out cohorts in subtle ways that maximise the inability of cohort members to detect the separation.