They are not talking about "technical superiority" though, but about "alive and kicking" and "work together pretty decently" and you followed up with a question of daily volume as somehow being the indicator of the maturity of the technology itself.
There are multiple reasons for a lack in adoption, of course. Network effects, FOMO and walled gardens, financial might and power of dominating competitors to name a couple besides just the quality of the tech itself. And it doesn't help when many people off-handedly state the technology is not good, because it is not yet as broadly adopted as the centralized giants it is trying to be an alternative too :)
The 'why' you have here is a more open question and there's a lot in there. Companies trying to make money from it, users not having seen many real privacy implications on a wide scale, police presence being up and down etc. etc.
In any case, if you want a point, whenever technical people bring up the technical superiority of X protocol or tool in a discussion, I like to ask myself this question. How many people actually use the thing that someone is telling me is so much better for the world? If it's so good, why is nobody using it for practical things? Have they used it before and there's a decline, or is it a new up and comer and it just hasn't caught on?
I think just asking the question sparks a valuable train of thought.