if other fedi projects are any indication, likely a unified API will develop. Mastodon’s API is supported by most other fedi projects, so you can use mobile apps interchangeably. If Lemmy becomes dominant then kbin would have to implement an API to match.
Missing replies has been a problem across fediverse for a while. There are some ways to mitigate it but they can be resource intensive. For example Akkoma fetches the missing replies when you open up a thread. It contacts the originating server’s API (not ActivityPub) and requests the details for the thread. It works pretty well but I’m not sure it would scale for Lemmy/kbin which is going to be designed for huge threads.
I hope a good solution is figured out and maybe even can be implemented by other software projects across fedi.
the ‘4D Chess defense’. we can’t keep saying that mistakes are actually intentional when there are so many examples of the mistakes, being made for the same reasons, by the same types of people (out of touch CEOs with terrible judgment)