I can't speak for everyone, but as developers we are trying to emphasis UX/UI work more. We have a dedicated repo now for user feedback, designs, and proposed solutions: https://gitlab.gnome.org/Teams/GIMP/Design/gimp-ux/-/issues We implement from there as we can, once consensus has been reached.

We also highlight UX/UI improvements in each new release post. Just like with coding, we rely on volunteers to help with this (you definitely don't want someone like me deciding on interfaces!) We have a couple active designers assisting us, but we're always looking for more feedback!