I do think there is room for a few good paid text editors in the world, but most people won't pay directly for them, though they might use them if they are bundled ala Google Docs / O365 Word.
I also paid for a few more, e.g. Notion, but I think it's better to focus on: There's definitely value in good text editors.
They can greatly enhance your experience with a system, e.g. if Samsung Notes was amazing I'd be much more likely to stick to using a Samsung phone.
That last category of people are also now likely to go create something themselves with AI, but don't really want to or can't start a business from it, so they may add it to the pile of free software others can use.
Not everyone HAS to profit from their work, though I do think those who make it their passion might benefit from finding a way to do that.