The design decision to feel "default-text" is awesome - text is a great foundation for a "custom workspace" product. But, it's only when the bulk of content is in Tables that things get extremely powerful.
Once Notion has in-line text references, ala Coda, the sky is really the limit. I think Notion nailed the UX and speed / performance.
Even if it's slow compared to Apple Notes, it's lightning fast compared to Coda, where "Documents" are extremely heavy, and relatively isolated.
Notion has a clean route towards eating Coda's most powerful functionality ([an incredible charting and formula](https://coda.io/formulas)). That's the kind of thing that a company as well-financed as Notion can dedicate a team to, and make incredible progress on.
Similarly, They can eat Coda's in-line text references, so your text can live-link to information in tables. A matter of resource allocation.
Coda, on the other hand, started from an "easier application builder" approach, like Retool for Excel experts. That's brilliant and powerful, but the UX creates a bigger dividing line between consumers and creators.
Notion feels enough like a normal word processor that consumers start doing crazy things without realizing it.