Developer Dan Gould has been documenting the growth of the technology in a few big tables on the Bitcoin wiki this past week.
"The BIP78 payjoin protocol has been gaining traction in recent years and is now supported by several wallets beyond merchants."
"BIP78 allows sender and recipient to negotiate a payjoin transaction over the web, by allowing both parties to contribute transaction inputs. This foils the primary heuristic strangers use to surveil Bitcoin users."
"In addition to BIP78, there are other ways to spend Bitcoin with inputs from multiple sources that are still fundamentally payjoin transactions, too. Having included them on the Payjoin Adoption page their relationship to payjoin should be examined."