I feel like you are from an older generation, not that there's anything wrong with it, but you probably no longer have the same needs as the younger generation. When I organize stuff, I don't always do it between 1 or 2 people. Once we were a dozen that went to an Escape Room, even more people were interested and even more were invited. It was barely organized days before. Sure it works coordinating through more direct means and people did that for a pretty long time, I feel like you had to when you had similar needs, but the thing is, there's a better tool for it nowadays which is Facebook. It's like saying you don't want to use the all good new framework because of the good old way that worked.
Also, it's partially true, people do mind being in direct touch, we had some people that just disappear from our events (and some of them came back using a pseudonym later on) because of that reason. It's a central way to put everything if something goes bad, this is where it's updated if anything changes. Again, it's like saying you don't need a bug tracker because you can easily do it using emails. Yeah, it works, but it tiresome to do it that way.
I personally don't care much about this tracking. It tracks mostly what I give it. I know what it does and I work with it. I'm not afraid of personalized offer, it's all good, offer me a new laptop for a great price, I would be happy to take a look and buy it if it does fit my criteria and my needs.
I don't want Facebook to know that I'm interested in software engineering? Well, maybe that was dumb to tell it in the first place (and in that case, I would use more private means to follow that passion).
I spend 0.0 hours per week on facebook, and 0.25 hours per week coordinating activities directly.
How much time do you spend on facebook?