@GavinChait the learning curve for p2p systems is not intrinsically any steeper than cloud systems, in fact there is a potential for it to be much simpler since much less needs to be concentrated in a single system. With generalized p2p the distinction between generalist and specialist data is actually much much easier - there doesn't need to be a specialist database or platform for each type of data.
neither wikipedia nor openstreetmap are p2p systems, and that is one of the reasons why they as platforms need to maintain paid staff to maintain data integrity.
there aren't any such systems, and there are good reasons for that having to do with the history of the platformatization of the web. the things that come closest are private bittorrent trackers which maintain excellent quality archives with next to zero budget in highly adversarial conditions.