Or when you just landed on the other side of the planet and don't have a good internet access (or it costs $$/Mb): the app is still expected to work, because you need your ride right now
Uber doesn't work without decent internet access though. Maybe you can make he argument for $$/Mb, but there's no point in uber creating the app so that you can get to the pay screen without internet when you need the internet to use uber.
Decent can still be pretty bad and still work. And of course it's worth it because a phone can find/lose it's connection all the time for a bunch of reasons even if the network is high quality and high bandwidth.
The whole point is the seamless transition. Would you want to sit there twiddling your thumbs in a potentially unfamiliar area, while the region's version of the app loads? Or would you rather just have it work?
This keeps getting repeated in this thread & I keep not understanding it. If I downloaded Uber & set it up with the payment method that I need, why would that payment method suddenly change at 1am in India?
The way this should work is when you set up payment option X, it downloads the relevant payment info & then you're set from then on without any other modules unless you add a new payment option. Likely pre-bundle the generally "global" options (Apple Pay/Android Pay since those are platform-native & credit cards since those are likely small implementations).
The real reason is that you will always have drop-off because the download phase is split in two (on the other hand you'll have increase in installs because the app size is smaller). That would need App Store integration with the loadable modules so that you could say "Install these payment features of the app". This may not be a win because again, it requires the user to do more work. Simple for everyday users will often win the day even if inefficient vs more optimal options that achieve that optimality by pushing complication to the user.
I recently was traveling. I landed at a new destination and checked the internet speed. Mobile via my tablet just outside the airport was theoretically as 50KB/second via Google speed check. However actually downloading a file from US servers was 5-15KB/second because of the latency (3000ms+) being so high that packets were constantly being dropped.
That's at best, 75 seconds waiting for a download. At worst it's 16 minutes.
On the other hand, I was able to get Uber on my phone and though it was painfully slow, it found a driver in under 30 seconds.
When I'm opening Uber at 1am in the cold to get a ride home, this is not the time to download a payment SDK update.