No, JoinMarket's maker/taker coinjoin protocol was was released in 2015. But the JoinMarket wallet software did add Payjoin as an additional feature later on.
Payjoin has skewed incentives: The receiver benefits from free UTXO consolidation when they get paid... but the sender pays this extra fee for them.
Also, both participants in a payjoin are a single point of failure since the anonymity set is only 2. That means any measurable divergences in onchain footprints for either transactor's ancestor or descendant transactions can deanonymize both of them.
...and even if the footprints of both payjoin participants are identical onchain, one of them might use an Electrum light wallet that syncs by sending all their addresses to third party servers. This would silently destroy the privacy for both users.
Payjoin was nice for Wasabi's 1.0's ZeroLink toolkit in 2019, but Wasabi 2.0's WabiSabi protocol allows direct payments in coinjoin. This feature nearly eliminates the possible scenarios where a user would prefer to use payjoin instead of batching their payment in a coinjoin, sending a solo transaction with cheaper mining fees, or just using Lightning for speed + privacy.
No, JoinMarket's maker/taker coinjoin protocol was was released in 2015. But the JoinMarket wallet software did add Payjoin as an additional feature later on.
Payjoin has skewed incentives: The receiver benefits from free UTXO consolidation when they get paid... but the sender pays this extra fee for them.
Also, both participants in a payjoin are a single point of failure since the anonymity set is only 2. That means any measurable divergences in onchain footprints for either transactor's ancestor or descendant transactions can deanonymize both of them.
...and even if the footprints of both payjoin participants are identical onchain, one of them might use an Electrum light wallet that syncs by sending all their addresses to third party servers. This would silently destroy the privacy for both users.
Payjoin was nice for Wasabi's 1.0's ZeroLink toolkit in 2019, but Wasabi 2.0's WabiSabi protocol allows direct payments in coinjoin. This feature nearly eliminates the possible scenarios where a user would prefer to use payjoin instead of batching their payment in a coinjoin, sending a solo transaction with cheaper mining fees, or just using Lightning for speed + privacy.