Back in the early days of the web, I always wanted an easy way to have a personal "presence" online, to stay in touch with friends and have a sort of virtual "contact list". Friendster (in its original incantation) was probably the best realization of that. I'd say that sort of thing was more or less needed & inevitable, at least at the time. Facebook originally started as a "better" version Friendster (and its successor, MySpace).
Today, Facebook is nothing like those systems of the past. It's now a horribly gamified, ad-saturated UX anti-pattern nightmare. I'm pretty sure that was also more or less inevitable, but for different reasons.