So how do you do that without creating a link to your real identity? That’s the part I find confusing. It’s not about Bitcoin itself, it’s about the process of converting the fiat to Bitcoin in a way that doesn’t leave a trace.
Simple way is to exchange cash for bitcoin with someone using p2p trading, this won't leave any trace.
For this you need to have someone in your local area who is interested in trading, and you can get connected in different ways.
Other way is by using decentralized exchanges and services like PeachBitcoin app, Bisq, Robosats, etc.
Having someone in his local area? That's not a very wise way to accumulate some Bitcoin this days, there are many Bitcoin still moving around with bad footprint on them, because they are stolen through hacks and other ways.
The funny thing is there is a track on such Bitcoin, centralised exchanges are laying low looking forward to where the Bitcoin will end up, I will never buy bitcoin from anyone living close to me or even my friends.
The country is hard, things are more costly and people don't care how to make money anymore, they can decide to turn evil in second, before you preach about knowing those close to you very well, we are human and change is the only thing that's constant with us.
What if the vendor in question were reputable enough to do business with him? Maybe because the locals would tell that he has no - dirty - BTCs, yet again, it may be a trap set.. You never know when misfortune would strike.