Pingbacks are back, baby! What is old is new again, except this time is centralized, so hopefully with less spam but also less independence once FAANG acquire the service.
When did we all end up so pessimistic? An interesting new idea with little more than an MVP, and we've already mapped out its whole demise.
This is fact. We need to get used to it and solve the tough problems: identity, moderation, spam, discussion quality, community norms, and so on.
Building a service is often easy. Marketing it is harder. Building something useful to a group of people in spite of human nature is probably the hardest.