Uber options from this year's travels around:

Santiago to/from airport. Much cheaper than other options, just know that you need to wait in the short-term parking area to pick up the uber, and uber is definitely illegal here so they insist on you sitting in the front seat (as a friend) and warn you to not say anything about being an uber if someone asks (also they hide their phone when closer to the airport). But overall good experience and the best way to get to/from Santiago airport.

In Buenos Aires, similarly illegal and had some unfortunate/bad experiences where multiple uber drivers cancelled on me after 5-10 minutes (or messaging me asking me to cancel which I refused to do). Got some uber credit out of it, but had to take a regular taxi in the end which cost more than what uber was quotng. But then again, at another time was able to easily get an uber at 1am in buenos aires after some bars and that was far cheaper than taxi. Lots of posters around the city warning that uber is illegal.

Lima Peru, uber works fine within the city or going to the airport. From the airport, it was kind of confusing to figure out where the pickup spot is, so ended up taking a cab.

Vietnam (various cities HoChiMinh, Hanoi, Danang etc), uber is the best way for short trips. For longer trips easiest to just flag down someone and negotiate a full day rate (or ask hotel to do it for you).

Cambodia/Thailand, found it easier and faster to just stop the next tuktuk and ride in it, or negotiate a full day rate. But uber did work in bangkok if needed late night once metro closed down.
LaPaz (Bolivia), also found it fast to just grab the next cheap cab.

Dubai uber was fast and very easy, best way to go unless you're on their metro line (in which case metro is better).

Karachi Pakistan has an uber alternative called Careem which is way more popular (but uber can work also in a pinch). Careem in general seems to be a thing around various arab/middle-eastern countries.