Oh, in terms of the risk of federation causing lock-in: it's inevitable that folks will add domain-specific extensions to try to force people to use their platform. This is no different to me sending you an attachment over email in some proprietary vendor-specific format (e.g. .ppt) which obliges you to install PowerPoint to read it.
This can be used for both good and evil. The evil scenario is above - rather than using an open standard like ODF, it provides a route to promote vendor lock-in. The good scenario is that it provides extensibility for technology that simply isn't standardised yet, and gives vendors a way to differentiate their product. For instance, if Oculus jumped on Matrix and started using it to negotiate VR collaboration spaces, it almost certainly wouldn't work with any other vendor at first... but it's good news for end-users who get a cool feature which some day may be standardised across all of Matrix.
The bottom line is that as long as everyone implements the common base line use cases in an interoperable fashion (i.e. IM and VoIP), then vendors having freedom to put proprietary/experimental stuff on top is just a necessary evil... as long as they don't break the baseline. It's up to us as consumers to then encourage vendors to make their extensions standards rather than exploit them for vendor-lockin. It really is an identical situation to email and MIME.
This can be used for both good and evil. The evil scenario is above - rather than using an open standard like ODF, it provides a route to promote vendor lock-in. The good scenario is that it provides extensibility for technology that simply isn't standardised yet, and gives vendors a way to differentiate their product. For instance, if Oculus jumped on Matrix and started using it to negotiate VR collaboration spaces, it almost certainly wouldn't work with any other vendor at first... but it's good news for end-users who get a cool feature which some day may be standardised across all of Matrix.
The bottom line is that as long as everyone implements the common base line use cases in an interoperable fashion (i.e. IM and VoIP), then vendors having freedom to put proprietary/experimental stuff on top is just a necessary evil... as long as they don't break the baseline. It's up to us as consumers to then encourage vendors to make their extensions standards rather than exploit them for vendor-lockin. It really is an identical situation to email and MIME.