(emphasis mine)
Bit odd how you could miss the only point OP was trying to make. Yes, if you know that TECH_X is used in production at BIG_CORP_Y, it's very helpful. I can tell you that in the BIG_CORP I work for, we quite possibly use or have used any- and everything for something. The point OP was trying to make is: What is that something?
Nail. Head.
If you want a one-liner to summarise my post, this is it.
FAANG size company can use in production much less mature software than most small companies. If they want to use X they don't need to wait when X will be mature - they can make it so for the use cases they have (which may differ from the use-cases you have). They can hire an X expert or dedicate a few engineers who will learn X and become X experts. Even if they will encounter a problem in production (not every bug can be prevented by pre-prod testing) these engineers will debug and fix it and with the help of CI/CD pipeline the fix will be in production in a few hours or days at most.
What would a smallish company do in a similar case - report a bug to developers and hope it will be fixed and the fix will be included in the next release which will arrive as an OS package / Docker image several months later.
I do not, it is how you gauge if something has been tried and tested in production for example Go. It doesn't hurt whatsoever knowing that Go is used in production by Google in various high demand systems.
The more companies I see using a product in production, the more I can determine feasibility. I just wish more companies would have technical blogs to describe their experiences.