I think the cost of the development (and distribution) license for the underlying framework libraries would be prohibitive.

Also, web sites and other tools (e.g. Obsidian.md) have come along and taken most of the RW customers away.

I agree they've taken most of the customers away, but I don't think that Obsidian (which is what I've taken to using) is anywhere near as good as RW. You have to hammer it into being a decent tool for GMs with additions.

Obsidian is better IMHO... much much better imho. It's much faster and vastly more flexible. The amount of time and effort I put into getting content into Realm Works... it was literally years... I have doubled that level of data entry in Obsidian in less than a year.

Looking back... I was constantly using Realm Works to try and get it to a point where I was ready to use Realm Works.

Where now in Obsidian I spend most of my time with absolutely no consideration for the data entry. It's done so I can focus on session prep.

If Realm Works bounced back with active development and active community engagement... I would be very unlikely to return.

There is a trick to Obsidian though... you need to control how deep you go down the rabbit hole. I have gone very deep (the nature of the making videos means I am always exploring new functionality) but I don't actually use most of it in my personal vault.