That's a good point. Google was sleeping on AI and wasn't able to come up with a product before OpenAI and they only scrambled to come out with something when OpenAi became all the rage. Big companies are hard to budge and move in a new direction.
Google and Microsoft have existing major money printing businesses to keep their AI business afloat and burn money for a while. That's how Microsoft broke into gaming (and then squandered it years later for unrelated incompetence)
The job hopping thing was definitely a trend, but I think it died with ZIRP. kinda weird to reference it now, but I guess it does have relevance to the state of some of these older services. The original teams are long gone