A big part of the treadmill is that frontends are seen as interchangeable low level investments steered by sales. Short term superficial requirement drive development often by an external team. Funding for sustaining them is scarce. So after a few years - the original team disbanded except maybe a small fraction and when the list of must have changes become too painful a new team is assembled and with it comes a need to differentiate itself from the legacy and assert control of architecture and purse.