Something we're trying to do about this on the Matrix side is MSC2716 (https://github.com/matrix-org/matrix-doc/blob/matthew/msc271...) - the ability to import archives of existing content into Matrix, and thus 'lock it open' and decentralise it for posterity: as long as one of the servers participating in that room stays alive (and the room is set up with infinite data retention, obviously) then the conversation will live on forever. (That MSC is also well worth a look for those interested in how Matrix works under the hood; MSC2716 was a surprisingly tricky problem to solve but it's basically finished now!).
Our first step will be to import all of Gitter's archives into Matrix - but we're then planning to add MSC2716 to all the existing Matrix bridges so that folks can use it to liberate chat history from Discord and Slack if desired, and avoid it getting paywalled/siloed/lost/held-hostage forever. We're also expecting to do USENET, mailing lists, forums, public IRC channels which have explicitly opted into logging... and generally archive as much possible in an open decentralised fashion, and ensure that gatekeepers can't lock up and blackhole info going forwards. After all, information longs to be free :)
Our first step will be to import all of Gitter's archives into Matrix - but we're then planning to add MSC2716 to all the existing Matrix bridges so that folks can use it to liberate chat history from Discord and Slack if desired, and avoid it getting paywalled/siloed/lost/held-hostage forever. We're also expecting to do USENET, mailing lists, forums, public IRC channels which have explicitly opted into logging... and generally archive as much possible in an open decentralised fashion, and ensure that gatekeepers can't lock up and blackhole info going forwards. After all, information longs to be free :)