This caught me by surprise too, but there is a ticket about it. Still a ways off fr being fixed I'm sure.
I've played a bit with iced but it seems like a bit of moving target and I'm not yet convinced by the ergonomics of Rust to describe a GUI. But it's OK I guess.
Slint looks interesting. I'm hoping to find some time to play with it soon. You can use it for free as long as you mention somewhere that your program uses it.