You described the majority of those as being about the perception of value rather than value.
>No one would advertise with Facebook if there was no value from purchasing ad space. The billions of dollars people spend is evidence there is value there for advertisers
No one is disputing that the advertisers are getting value. The pursuit of advertiser value at the expense of users is the complaint.
Which is why they weren't useful to bring up.
A more interesting thought experiment is where that threshold is before the lack of value invigorates the energy needed to migrate. That's part of why I put the boiling frog metaphor there. Rate of change definitely has impact on perceived value.