Looking at this page, https://slite.com/use-cases, I feel like this kind of product is an anti-pattern. The reason that it's hard to find things in slack or docs is because these apps do not well understand the underlying structure of the data and so are relegated to either full-text search, or some sort of naive clustering algorithm. Although Slack has made some advances here - such as adding context-specific buttons for actions.

Will Slite do a better job at understanding our bug reports than Github? Or understanding our applicant tracking system then Greenhouse? Our customer support than Zendesk? Every one of these tools have a search feature.

The value of Google Docs is that it stays out of my way, lets me create freeform notes, and integrates with the rest of Google. Probably the same for Paper, or any other team notes solution. Once something gets complex enough, creates work for teams, or is mission critical, it either needs to be actively managed by a team member, or move into an automated tool that does that management for us. I can't imagine the solution would be to centralize all these disparate workflows in a tool like this.