No one would want to build applications for a platform that lacks widgets capable of properly displaying, formatting, and editing text.
Is the idea that people are only going to be running Iced applications in COSMIC? It feels to me like the realistic option would be that, if COSMIC ever becomes daily-drivable, people would still be using GTK applications with it, at least at first. Might as well use a GTK text editor then? Then System76 could focus on building a text editor after COSMIC is a thing, and COSMIC would hopefully arrive sooner (or even at all - this looks like the path to burnout).
I mean, I don't really mind - I'm pretty happy with GNOME. All I'm saying is that if I were the project manager, I'd worry about delivering something and not burning people out ("focus is choosing what not to do" and all that, and the last 20% of the work taking 80% of the time). But in the end I'm just a random person ranting on the internet, of course - I do actually hope that I'm wrong.
But a diff viewer in the text editor... It just sounds like folks are eager to jump on shiny new things rather than finishing something, from the outside 🤷 Looking forward to be proven wrong!