It is worse because of:
Loss of longevity
Promise of employment ... a promise which management has a terrible track record of keeping
No job security ... company can furlough Delta pilots while hiring at Endeavor
Union has compete with itself against other pilots in the Delta system
Junior FO'S have better seniority rights than senior Captains
Pilots are trading empty promises for money and holding company's costs down with a corporate shell game
QOL issues. Pilots can not bid equipment or bases within the divided system
Extra expense - separate certificates require redundant management structures and each Certificate is in fact another fleet type under the regulations with different mechanics and crews.
In efficient - airplanes are constrained to arbitrary scope limits rather than their Certified capabilities.

That's just off the top if my head on my phone in the tag office.