Brazil ended with a third system: Pix. It boils down to the following:
The money receiver sends the payer either a "key" or a QR code.
The payer opens their bank's app and use it to either paste the key or scan the QR code.
The payer defines the value, if the code is not dynamic (more on that later).
Confirm the transaction. An electronic voucher is emitted.
The "key" in question can be your cell phone number, physical/juridical person registre number, e-mail, or even a random number. You can have up to five of them.
Regarding dynamic codes, it's also possible to generate a key or QR code that applies to a single transaction. Then the value to be paid is already included.
Frankly the system surprised me. It's actually good and practical; and that's coming from someone who's highly suspicious of anything coming from the federal government, and who hates cell phones. [insert old man screaming at clouds meme]