Tragedy of the commons explains everything.
Individuals at Google are incentivised to abuse the collective reputation for personal gain.
It always seems that the towering reputation of Google is an unassailable monolith that will never be shaken by any individual. So every individual harms it in their own tiny selfish way, gaining promotions, KPIs, or pay bumps as a reward for their behaviour.
Decades of promoting the selfish, commons-destroying people eventually results in an organisation that has these values entrenched in its upper echelons. At this point, the demise of the enterprise is inevitable, as the commons is destroyed in bigger, more obvious ways, by people now thoroughly empowered to do so, and surrounded by people competing with them for the right to also destroy the commons even more.
Cash reserves and the intangible value of lingering external brand perception can drag this out for a surprisingly long time, but the direction will inevitably continue downwards.
In other words, it is precisely "reputation" that enables this kind of atrocious, value-destroying behaviour and quality erosion.
Companies without reputation are too busy building it, and can't afford even the slightest slip up.