As a seller using an account that has your mobile number (like an opay account that removes the first zero in your number and uses as your bank account ) can be a mistake if you want to protect your privacy.
Well first, you can either be the buyer or seller doing p2p on exchanges. The way you placed your first point made it seem like we only sell coins on p2p platforms. I agree with you and I've said this several times on the forum. Don't give out your real phone to anyone on p2p platforms. They usually request with in claims of fast response or transactions, but most of them on those platforms are scammers.
We know there's still possibility of them messaging you directly through your bank number, but then you can as well avoid any transactions that's not conducted on the P2P platform or else you would face the risk that follow.. then p2p use to be a safe heaven for us to trade our coins. But it has turned into something else today.. let's stay safe out there..