Lol, that is certainly true and you would need to also set it up manually which even power users might not be able to do. Thankfully there is an easy to follow guide here: https://ai-guide.future.mozilla.org/content/running-llms-locally/.

It gives you many options on what to use, you can use Llama which is offline. Needs to be enabled though about:config > browser.ml.chat.hideLocalhost.

Bluesky uses AT Protocol and Mastodon uses ActivityPub which makes it impossible to federate. Bluesky does allow you to host your own servers though, so you can consider its own fediverse.