When I close the program my dialogs get restored so I'm not sure what's happening with yours. You may at least want to update to 2.10, there should be a Flatpak

When I close the program my dialogs get restored so I'm not sure what's happening with yours. You may at least want to update to 2.10, there should be a Flatpak/Snap for it. As of GIMP 2.99.8 the brushes window is still the same. I think all that is due for a redesign, and the menu bar should probably be gotten rid of completely. But someone who is a skilled designer will have to contribute in order to figure out a replacement. The mockups I put elsewhere in the comments here might be a place for someone to start.