I believe he's referring to kbin as an app that competes with the lemmy app itself. It's a bit off, but not entirely. The problem is that kbin introduces things that are not entirely lemmy compatible. So it feels like a new app, meaning it feels like a fragmented ecosystem. It's not entirely wrong, and it does make for a poor user experience when it comes to onboarding, but overall the thats largely the intent of the fediverse: provide options. You should be free to create your own version, however compatible you choose to make it, and add whatever features you want. Users are free to use it or not. No one can disable all functionality such as reddit shutting down all third party apps. This is by design and why you'll see many great apps pop-up. Kbin being one of those options.

I use vaultwarden as my bitwarden backup. I pay for bitwarden premium because it's too critical of a service for me to not pay for access/support the service, or to expect my self hosted option will be sufficiently reliable enough.

That said, as a backup option, I run the vaultwarden addon in home assistant and just periodically do a manual export from bitwarden and import to vaultwarden. This is usually good enough for me, but glad to see this thread with some other options. Will be exploring some of these too!