Notion is the classic tale of starting small and growing into a bigger vision
Notion started by tackling a boring but very ubiquitous problem: documentation. Most folks settle for Google docs, Notion saw a better way with more customizable, block-based components
It had to grow out of just documents while holding onto its initial value prop.
You can observe that Notion tried to balance their changing product with their core value prop in the 2018 landing page.