Centralized content indexing is compatible with decentralized content. Like Google. Question is incentives for the indexer, what will be the profit model.
Discussion
Indexing is not the same as suggesting content. Even if a sorting algorithm is fine tuned for your preferences it’s a hard problem. There must be some centralization of your history. Maybe its not tied to google account… dont have enough technical knowledge to really say how feasible the whole thing is.