> some banks still require an app for 2FA, or windows...

Are these limited to only "approved" apps? Usually you can add an auth to an app via a qr code or string. Why can't people use whatever auth app they want, or even just roll their own?

I think this depends on the ATM. OCBC ones do allow sending money digitally.

Oh, and you can always send money by withdrawing cash and giving it to the other person physically.

Or go to the bank branch, or write a cheque.