(Quite literally - Uber sold off their SEA operations to Grab in exchange for a stake in Grab, when Uber exited the SEA market)
Uber also owns a significant share of Grab.
Cash is not only accepted but in specific Indian cities expected , I.e. the driver will call you and if you don’t offer cash they will cancel the booking or won’t show up at all .
Uber and others pay out on a weekly basis. Cabbies would rather have the cash now. And by cash, they mean a direct payment outside the app. Typically this would mean a direct transfer via UPI.
Each country has and always has a lot autonomy on features and services offered . Just their booking methods in different airports can have lot of variation , OTP workflows in geos with high no show rates , transportation options like motorcycles or Tuk tuk or public transit integration all are unique to many locations
Consolidation and exits happened for variety of reasons i strongly doubt it was ever because of product features or lack thereof
Use Grab a lot and I don't consider it a super-app. It truly is the Ride Hailing/Food delivery service app to use in certain parts of SE Asia. WeChat has a massive ecosystem in that its chat, payments, and a million company built "apps".
In many bank apps they will do travel, stay, cars, vacations, shopping and other dozen things like that .
It is not just banks , airlines do it too, they are so good at it, they are sometimes called finance companies with incidental air transport business.
Somewhere there's a Dr. Strangelove kind of comedy where a wrongly addressed tweet sends the nukes flying, because the competent engineers on X will make an API over tweets, you see...