The same can be said about COSMIC from System76, they have had serious disagreements with the direction of the project so they said "fuck it, we're just going to build our own desktop and run it the way that we want to run it".
Could problems just be resolved upstream, maybe. But they have decided that this time has passed, any attempts made didn't go the way they wanted so they've decided to go off and do their own thing.
Maybe in the long run all of this is a giant waste of time, GTK3 can no longer be saved, building a desktop on an immature toolkit like Iced just won't work. This is completely possible but I have nothing but respect for developers who actually take it upon themselves to try and resolve what they see as a problem by sitting down and just writing some code.