This 17 year old Shimano Deore RD-M575 derailleur has been on my Trek 6700 since 2004. After replacing the derailleur hanger and cables, it still shifts like new! : r/bicycling
Cannondale Hanger Compatibility - Shimano XT RD-M8100 | Mountain Bike Reviews Forum
Derailleur hanger types? How to find it? What is dropout? - Elanus Parts