The products must change because engineers need to do something to show impact and get promotions. Therefore, if the product has reached the maximus of quality, but you need to change it, you end up with zugzwang. Always follow the incentives.
I would argue it's not the engineers that need to do something, rather middle management that needs to show 'results' and show that they are there to bring 'value', even if it's not real value. I seriously doubt changes like moving fingerprint sensor under the screen come out from an individual contributor.
