But the G29 is supposed to work on PS5, according to Logitech.
Yes but its release date is from 2015, at that time the only solution was the speciality controller approach. And just recently Sony decided to no longer allow speciality controllers for most PS5 games.
Newly released PS5 certified controllers, such as the new Thrustmaster one, could use a different solution that potentially works with the XIM too.
I should have checked the release date of the G29 prior to writing my comments above as that made it pretty clear that its just a speciality controller.