I’m also curious how people used to do it in the earlier days, like in 2014 or 2015. I guess it was easier back then but I don’t know what the usual methods were. Were they just doing regular bank transfers or was there something else people used to stay private?
If someone with real knowledge/experience can explain how this is done in practice I will be grateful for and than you.
Early years of bitcoin like 2014 or 2015 as you said in OP, this forum served well for that purpose and I also think that the forum is still good for this purpose. You can go to your local board or also in the global board and request P2P trading with any member of this forum, especially the ones that render the service. You can send first or vice versa, you don't have to worry yourself if you have seen the user's trust score and believe they are trust worthy.
If I read old threads, I saw how people traded and leave feedbacks, but today the feedback space has lost what it's supposed to be. Person can easily give positive feedback because they love the person without any evidence of trustworthiness.