How can you be 100% sure that the technology is coming?

It seems like every few years or so, the AI/AGI/Metaverse future is pushed back a few years. I don’t understand why it’s widely accepted that the future is basically deterministic. Many people are working in the area but we don’t know that it’s actually possible for AGI to become real in the first place. I don’t see how anyone can know that the future isn’t going to be human level in 2090 but not 2080. What am I missing?