So, no buying with fiat via exchange?
No in this case. However, strike app is using the bitcoin network as a payment rail. strike keeps your fiat. Let us say if you want to pay a merchant, strike converts your fiat instantaneously and sent it to the merchant. Unfortunately, it works only in the USA and El Salvador.
I still use exchanges for HODLing. It is not worth buying sats upfront in the exchange for everyday spending.