I'd really like to see some kind of Slack-collaborative-notetaking-email-client-CRM-CMS-filesystem-hybrid that can hierarchically unify my view of any tag or su

I'd really like to see some kind of Slack-collaborative-notetaking-email-client-CRM-CMS-filesystem-hybrid that can hierarchically unify my view of any tag or sub-tag or cross-cutting-concern across all the ways those neurons in my brain fired. "Where did I put that thought" currently requires a search across a half-dozen apps and tabs. But even a unified search wouldn't cut it; sometimes you need that hierarchy (or multiple hierarchies) to take a step back and realize you need to drill down into something you would have forgotten to search for in the first place. It's the holy grail of UX problems, but whoever solves it will have a unicorn. Notion.so comes closer than anything I've seen, but its lack of interoperability makes it difficult to be this ideal nexus of my thoughts. I still use Evernote actively as my main thought-dumping-ground and meeting-note-taker, though more out of habit than anything else at this point.