The thing is, in my experience as a user Facebook (the product, not the former company) is absolutely riddled with bugs. I have largely stopped using it because I used to constantly run into severe UI/UX issues (text input no longer working, scrolling doing weird things, abysmal performance, …), loading errors (comments & posts disappearing and reappearing), etc. Looking at the overall application (and e.g. the quality of the news feed output), it's also quite clear that many people with many different ideas have worked on it over time.
In contrast, Google search still works reasonably well overall 25 years later.
One of Google's major cultural challenges is imposing the move slow and carefully culture on everything though.
The flip side is of course that I could complete 4 rounds of QuickExperiment and Deltoid to get Product Market Fit, in the time it takes to get to dogfooding for any feature in Google.