Earlier quoted context omitted.
https://en.wikipedia.org/wiki/Pareto_principle
I mean, it's possible, but the organisation would need to be extremely disfunctional for that to be the case - that's the level of bloat I'd expect out of a government agency not a private corporation. If you have teams where 8 out of 10 people do literally nothing or pretend, it should be obvious.
It says that 80% of the results come from 20% of the sources. That's not 8/10 people are doing nothing, but rather 8/10 people are doing things that only contribute to 20% of what makes Twitter Twitter.
On any given team of ten, it's likely that the entire team is in either the 80 or the 20 bucket, by virtue of what they're working on, not by virtue of how hard they're working or how talented they are.