i think there's a couple of reasons for optimism:
1. high-speed net access is becoming more and more common; higher speed help makes the possible overhead of distributed solutions less of a barrier
2. there is more awareness now of the downsides of having a centralized provider. many youtube creators and users have been burned by google; i think that'll generate real demand for a decentralized solution.
3. existence/arguably success of decentralized currencies provides a lot of psychic energy/motivation for making decentralized things.