The logic changes can be done without destroying investment in the current ecosystem though. So they are really handled separately in terms of planning/budgetin

The logic changes can be done without destroying investment in the current ecosystem though. So they are really handled separately in terms of planning/budgeting. Also, a lot of the problematic issues are related not to fixing the local code, but dealing with stuff like external systems or pre-existing legacy data that you need to be able to read back after 30 years from cold storage.