Company success is often about judging timing... too early or too late == death both cases. Super hard to do.
This generation is risking that there won't be a next big thing, and so someone smaller but more focused comes from behind and slowly takes over while they are focusing too much energy on looking for a next big thing that never happens. A more focused organization would better look after the core business and not be disrupted by someone who does their core business just a little better.
I can't tell you which answer is right (ask me in 30 years), but I can see possibilities.
My point was more of a warning to startup founders and investors. They should not assume that Google and the others will be too slow to respond to a competitive threat that a startup poses or a big opportunity that a startup creates. They will pounce aggressively, and either acquire or kill the startup. Complacency about FAANG is very very dangerous to the health of a startup.
Basically to become that successful, companies have some hit product that becomes their golden goose. All data in the world says that a dollar invested in keeping the golden goose alive and healthy is the optimal way to invest that dollar. No one in the company (not execs, or accountants, or engineers) would want to disrupt this good thing that's going on.
Like, suppose that technologists/engineers make rational data-driven decision - look at this huuuge pile of data that validates the decision to continue doing the same thing over and over again.
At that point the business model and original product are baked into the companies DNA, and despite new things coming along, they really can't even imagine what it's like to do anything else.
The ability to reinvent is truly the secret sauce to business. Very few execs can do this for their organizations. If someone could do it reliably and predictably, they'd instantly be compensated $100M+ and dropped into any of the companies you mentioned to 'turn it around'