We just returned from a 10 days trip in Mexico, equally split between MEX and CUN and we used Uber everywhere with no issues (aside of the trip from CUN airport to the Hotel Zone, but we already knew that Uber would not pick up from the Airport).

We did follow some of the advice read on this or another similar thread on FT and thus only booked Uber pick up points from safe spaces (Hotels, Restaurant or right next to some Police vans when we where near the Cathedral square).