How does UPI actually Make Money?

Then you don’t know anything. Main income is interest income. The amounts you keep in the wallets don’t earn any money for you but for them. This is the main source of income

None of the things you mentioned make good revenue, you missed main source

Recharge karne par 3-5 rupee cut karte hai , wo kya hai

The most important they sell spending data 🪬

You need to do more research.. they earn a lot of money

What about information gathered