It’s there in the Izzy repository

In the US maybe. Even in western Europe, 10k $ or € is a buttload of money per month. Something like 4x the net salary of a backend developer here in Belgium where I live.

Not really. Helix is closer to Kakoune which is based on the modal editing of Vim but reimagined a bit.

There’s a pretty simple reason. It’s that developers don’t have to spend the time to package for every single distro. I know I wouldn’t, I’d just focus on packaging for the distro that I use and flatpak. Having flatpak also means that some less known distros start with a big amount of apps available from the get go with flatpak.