I'm looking forward to Blitz personally. And I don't think it's true that it's the only complete enough solution as there are many in Rust like slint, iced, egui etc.
It's not actually about paying money or not, I've signed up for many a patreon or what not to support open source projects I use. I fully believe in paying people for software. But for core things like this I do prefer MIT/APACHE.