As others have pointed out, there are benefits to Facebook et al, both individually and collectively (though some people may ignore the latter) however there's also great harm being done through these platforms, from the creation of echo chambers to data collection (personally, I'm more worried about the former, I don't really care about privacy wrt getting ads sent to me).

So I don't blame Facebook for building a platform people want to use, but I do blame them for the damage it's causing. People that care strongly about the open web (not really me, honestly, as long as it exists I'm content, imo people don't have to use it) likely feel similarly.