That's why I made Fluski. Some of its characteristics are an infinite outline of pages, and that all blocks are collapsible and expandable. Coming soon bi-directional links, offline mode, databases, and much more! If you find it interesting, I would love for you to try it and hear your feedback! - https://fluski.com.
Also, there is a short Demo video in the Product Hunt post: https://www.producthunt.com/products/fluski