That is not what I asked though. Every experience is subjective. I’m asking how they envision this being a good business model.
Every bootcamp grad who can whip up a database backed web app can build a note-taking application that covers the major features. There is literally no defensible moat here and the incumbent is giving away theirs for free. What feature will you compete on? There are limits to how much innovation you can add to “storing rich text in the cloud”.
I suspect it's a combination of the intense passion people feel to work on this problem and the small user-base needed to support a small team to do the work.
I'm not so good at ballparking operational expenses, but Supernotes 2 probably needs somewhere around 2000 users to break even, which probably isn't hard to achieve.
After that, the founders are fully supported to pursue their passion. Sounds like a great business model for someone who wants to do this, and I think this is why you see a profusion of utility apps with ~$10/mo pricing models on the market today.