Just be a good exchange. Transparent and licensed and always fair fees. Make it better faster safer than a bank, now thats how you drive adoption man.
People in the crypto space needs their services for convenient and reliable means of crypto transactions, and also to reduce the chances of being scammed in two party p2p.
We're talking about cexs here and that to me has almost nothing to do with p2p.
CEXs being more secure and transparent is an improvement of system, not of network. I see network improvements to be what secures p2p more (talking about smart contract and escrow all on blockchain).
Believe me, if you take proper precaution with p2p you are way safer than using any CEX.