I was not aware about that. Thanks for letting me know. Sometimes I'd wish that OpenBazaar would accept a diversity of anonymous cryptocurrencies into its platform (like Monero or Grin) to provide better privacy to the buyer. I'm not saying that Zcash doesn't do its job well for preserving people's privacy. But there are far better coins out there with higher market capitalization than ZEC.
Anyhow, it's a good thing that OpenBazaar's code is open source. In the future, we could experience alternative versions of OB with that are much more oriented to privacy/anonymity. A forked version of OB that would use Tor (or I2P) by default, and would accept a greater number of privacy coins than the original version would be the next big thing for decentralized e-commerce.
Speaking of marketplaces, there are a plethora of decentralized solutions today that would prove to be highly beneficial for both the buyer and the seller. We've got Syscoin's Decentralized Marketplace, and the Origami Network (which runs on top of the ETH blockchain). I think this is more than enough for anyone looking to buy/sell items without the need to worry about government surveillance or paying hefty fees to a third party. With these solutions, both the buyer and the seller are in complete control (instead of a third party like it's the case with eBay and Amazon). This is much better than using or creating a marketplace within the darknet, in my own opinion