Seconded on not bothering with getting a local SIM, particularly now that they've made it even more difficult and bureaucratic. There are things for which it's easier to have an Indian phone number, but the majority of those are also things for which it's easier (or mandatory) to have an Indian bank account. Food delivery apps work fine with U.S. numbers.

As for Uber, while it doesn't seem to be possible to add foreign cards to an account Uber thinks is Indian, if your Uber account is tied to your American number and already has an American card on it, it'll work fine. I've charged every Uber ride for 2+ years in India to an American card, which is great fun when I have to call fraud prevention for something else and verify that yes, these Uber transactions for $1.23 and $1.80 are also legit.

Apple Pay works fine in India. Google Wallet will block your access to see or change anything with your payment cards but it will still make payments from the default card when tapped.

Setting up UPI as a visitor is probably significantly more work than just paying cash.