I personally haven't used a dex before, but I want to assume that users also carry out a normal bank transfer when paying for a coin, and receives a payment when selling, right?.
If someone pays to your own bank which I believe is registered under the surveillance of the same governmen, then there is literally no privacy there. I want to assume that the essence of using a dex for p2p as far as Nigerians are concerned, is to limit our identity that we issue out(like in the KYC).
I might be wrong, but that's my own opinion.
The purpose of using decentralized p2p like Bisq is to completely buy Non-KYC Bitcoin, no registration, no KYC, you just create an ad and wait for a potential seller - If I send fiat to you and you send your coin to my noncustodial wallet, no 3rd thirty, no KYC, it is considered a Non-KYCd coin and can't be link to my personal identity..
You can also get Non-KYCd coins through Bitcoin ATM with credit cards ( you can also buy Non-KYCd credit cards) without ID. Trading on Bisq or other DEX p2p platforms are way more complicated and takes time due to low trading volumes.