If you want to save 1000ksh but you need to hail 3 or 4 drivers to take your price, then that annoyance is the cost.
Uber's algorithms make it difficult for drivers to cover the cost of doing the driving unless they can get high tippers or lucrative fares regularly.
I'd also learned that since Uber doesn't want to tell people they can't find a driver, they will start at a terrible price, then if no one accepts the trip, the payout gradually increases until someone acquiesces. Unions would break this system of shortchanging the drivers by not accepting anything under the minimum level.
When I last visited Argentina Uber was using the official exchange rates which were just fantasy numbers. As soon as you match with a driver they'd message you and you'd negotiate the cash price. Then the ride in the app would be cancelled.
Uber didn't mind because they were still getting the ~$1 or so cancel fee for basically being a messaging app.
Well, in defense of uber, we have monopoly cash. As of today, they should have applied "dolar tarjeta", the drive probably negotiated some overpriced "dolar blue"
In either case, I'm sorry for your trouble. Idk if it is still like this, but it should be better to grab an uber than a cab here. If the cab driver recognizes you as a tourist, he will do a detour just to add Kms to the bill.