I wasn't using Notion for it's collaboration features, but as a personal wiki/knowledgebase/note taking application.

Basically, I want an app I can run on my desktop and phone, I can shovel every random thought, link, idea, code snippet, etc. into it, and I can find it quickly.

Joplin does this. Notion does this. Notion also has a lot of other features Joplin does not, true, I just didn't care about any of them. :)