It's too easy to get scammed. So why would somebody want to buy something from somebody using bitcoin on this forum? I mean there is no way to do a bitcoin chargeback and you can easily hide your address with a VPN.
because it is much cheaper to buy here on the forum compared to some online buy and sell sites. plus people here are using escrow to ensure the safety of both parties while doing transactions. and other payment methods with chargebacks like paypal can lead to scamming , that is why bitcoin is still the best option to use.