UPDATE: I found this issue explaining the relicensing of rust game engine Bevy to MIT + Apache 2.0 dual. Tldr: A lot of rust projects are MIT/Apache 2.0 so using those licenses is good for interoperability and upstreaming. MIT is known and trusted and had great success in projects like Godot.
ORIGINAL POST:
RedoxOS, uutils, zoxide, eza, ripgrep, fd, iced, orbtk,...
It really stands out considering that in FOSS software the GPL or at least the LGPL for toolkits is the most popular license
Most of the programs I listed are replacements for stuff we have in the Linux ecosystem, which are all licensed under the (L)GPL:
uutils, zoxide, eza, ripgrep, fd -> GNU coreutils (GPL)
iced, orbtk -> GTK, QT (LGPL)
RedoxOS -> Linux kernel, most desktop environments like GNOME, KDE etc. all licensed GPL as much as possible
GPL libraries have an advantage in their legal power. MIT libraries have an advantage when users have to choose between 2 libraries.
All other things being equal, users will use more permissive libraries. So unless maintainers put more effort into the GPL, a MIT one will gather more users, which attracts more maintainers, which ends up in more MIT libraries than GPL ones existing.