Why should I not build a note taking app?

I have been wanting to scratch my own itch of a perfect note taking app for the past 1 year.

I have hit a lot of roadblocks during this period, some of them including

• It is fucking hard to get WYSIWG right with real time collaboration.
• Losing motivation.
• Getting distracted with work.

I am thinking of building an app with the following features, a lot of them might be similar to notion:

• Realtime collaboration on the note.
• One click publish as a blog where people can comment and thumbs up.
• Focus on performance and simplicity over added features.
• Can drag sections and list.
• First class Markdown support.

The desire to build this thing keeps bringing me back. I am anticipating responses like its a crowded field, you should try something else. Maybe that is the case, but still wanted to see what you all think.

At best I imagine release parts of it open-source and the product as a freemium tool. At worse I can just release it as open-source and call it a day.