Not true : you move to the standard FO tables after you achieve an ATPL or two years whichever comes first.
So the maximum amount of time as a Junior FO is two years, and then you move to standard FO salary - CPL or ATPL. Again don't take my word for it call Simon Lutton from your own federation.
The "no command time" - career FO you will remain view on these cadetships is just a red herring. Qantas upgraded cadets , gave them command time , Jetstar has all those approvals - let's face they are Qantas. Rex is upgrading cadets, as has Qlink who still has Q cadets & people from their own traineeship.
So the "not enough command time" line is cute, but does not reflect reality.
The issue people have is one more cadet is one less direct entry place