People who don't use LinkedIn at all?

I know some senior staff engineers at FAANG who haven't used LinkedIn in years. I'm not talking about just not making or reacting to posts they haven't updated that they switched companies (all within FAANG), got a promotion or anything in at least 7-8 years. It literally looks like they got laid off and left the field entirely as junior devs based on their profile when they are objectively thriving (still in this job market). Does anyone else know people like this?