I tried that before in OKX direct exchange BTC and ETH but my problem is the rate is a bit far if you don't converted it first to USDT. That's why I suggested to exchange it first to USDT before going to P2P to exchange it into fiat.
The only cons of this you would need to pay trading fees after converting them into USDT.

If you see a good offer on P2P with direct exchange of BTC/ETH/XRP higher than  USDT then why not you can trade it into fiat. We are not the same I guess but for me, even it's a small amount I always coverted them into USDT for a better offers/rates.

I tried that before in OKX direct exchange BTC and ETH but my problem is the rate is a bit far if you don't converted it first to USDT. That's why I suggested to exchange it first to USDT before going to P2P to exchange it into fiat.
The only cons of this you would need to pay trading fees after converting them into USDT.

If you see a good offer on P2P with direct exchange of BTC/ETH/XRP higher than  USDT then why not you can trade it into fiat. We are not the same I guess but for me, even it's a small amount I always coverted them into USDT for a better offers.