P2P trading is not very popular. When bitcoin began, P2P trading was quite popular, as there were few centralized exchanges yet (or none, depending on your location and fiat payment methods available) and as exchanges did emerge, they were getting hacked left and right. So the P2P exchange methods were crucial as they provided the ability to acquire bitcoin, and the ability to liquidate your bitcoin (mostly miners and those "cashing out" after some nice gains) to those who had no other options.

That specific use case has not gone away, it's just that today centralized exchanges (e.g., Coinbase Pro, Binance) and brokers (e.g., Swan Bitcoin, Robinhood) have made access to bitcoin quick and cheap. Along with that, exchange hacks are fewer and far between than ever (though individual account hacks are still a thing but responsible use can all but eliminate that risk). [and #DeFi smart contract hacks don't count -- that's a completely different animal]

Today those engaged in P2P trading (to acquire some bitcoin or to liquidate some bitcoin), are doing so mostly to maintain financial privacy, at least in the western countries, where centralized, KYC'd exchanges and brokerages are abundant. There also are traders doing P2P trading for the profit from performing arbitrage, so privacy is not their reason for participating. So P2P bitcoin trading then exists solely for the tiny fraction of privacy-minded bitcoiners, who are a small fraction of the bitcoin ecosystem, which is a fraction of the wider "crypto" ecosystem, which is a relatively small fraction of the entire population.

A local group then is an even tinier segment -- those privacy minded bitcoiners who are in a local area or some connection to someone whois local.

And to slice that segment in to an even smaller segment, if I am looking to buy right now, that trading group might have two dozen people in it but I'm only interested in the fraction who are willing to sell to me, at this particular moment in time. It's the coincidence of wants problem.

So I'm not saying this can't work, I'm just saying if it does it will be due to a fair amount of persuasion, and determination, and luck, for it to become a useful endeavor.