Be careful with that thinking. That way can lead to complacency. Big tech loves embrace, extend, extinguish
I could see a corp like Microsoft or Google or someone else seeing long term value in federated services. They could create a service utilizing the technology and spread it to their user base. Slowly add in some special sauce to their own version of it to attract more people to their part of it. Then break compatibility with everything else to stop someone from stealing users back.
Some subs went into restricted posting mode and made it so the only post in the past 2 days is that Reddit is killing 3rd-party apps. I’m not sure how you are expecting r/all to actually look. Even if every major subs closed their doors forever, as long as there is any activity on the site r/all will be populated.