The alternatives already exist and they are build on Nostr and it has different apps/clients to interact with that protocol. For example Olas is a Instagram-like and tik-tok-like app, and there are also many twitter-like or mastodon-like apps such as Amethyst or Damus

I really hope so, it should be taught, because for me it was a slow learning process. First I started using Obsidian, and moving all my notes from Evernote, Notion, and others manually. After that I moved to Logseq, which is like Obsidian but open-source. And the last step was using an open-source syncing tool (Syncthing) to have my notes synced locally in all devices. And now I have been 2 years self-hosting my notes in a really easy way.

Hi! Nice to meet more people in that rabbithole :D