My hot takes on all this:
  1. We were always able to get a small group of nerd enthusiasts interested in using bitcoin as a payment system, but that never scaled to more than a tiny group. "Normies" were never going to jump on board with that (and that actually includes a lot of loudly self-professed 'bitcoiners' who could never be bothered to actually use the thing).
  2. But ... Bitcoin was never a payment network, it was always a monetary network. The 2012-2014 excitement about getting bars to accept it was never the point. So ...
  3. Lightning network is the closest thing we have today to what could be a well designed payment network on top of Bitcoin. It's not 100% there yet and there are some deep structural issues related to security (DOS) and privacy (receiver) but it's at least conceivable we'll fix them, and today Lightning works very well (I use it a lot for online and even in person payments). OpenBazaar was way too early for that, but I think they maybe were in the set of people who grossly underestimated how promising it was in the 2017-18 era. The thing is, even if they had gone balls to the wall on LN they were way too early to take advantage; it was realistically 3+ years before mobile software had gotten good enough and reliable enough to use it. Even now, we are not quite at the userbase level for a big p2p trading market to develop, though it's a lot more realistic nowadays.
But aside from all that debate, trade of physical goods is a really tough market it seems like. That's why Bitrefill (and I guess paxful, though I haven't tried that) had the right idea: gift cards and phone refills are very uniquely genuinely valuable pure digital tradeable goods. The whole shipping thing is so problematic without huge economies of scale, forcing locality in something that intrinsically wants to be international, plus the trust issue of waiting for long periods.