Gnome has different goals than KDE. The idea behind gnome development is to keep it as simple as possible. I think a lot of people around gnome went way to far but libadwaita is the right direction. GTK4 is very powerful despite what people think.

Hopefully the leadership will get more involved with average users. The problem with gnome as it stands is that they don't have a good understanding of what is actually used. I think they should absolutely not follow KDE as KDE is very cluttered. I like the minimal menus and clean design the problem is that the gnome UI design guidelines don't specify how much settings to retain. It just says remove stuff that may not be used which is a train wreck.

I wish they would better leverage gnome extensions to do testing. They could have experimental features be extensions that people could try. Combine that with some sort of feedback system and you can rapidly test new things.

I also think the guidelines should specify what is considered necessary as far as options go. Gnome keeps things streamlined and well tested but I've noticed some app developers strip out elements they don't think are necessary that end up causing major issues.

Lastly they should work with the Mint team to combine efforts. I think they have similar end goals and it would be beneficial to work to create shared standards that are used across desktops. I think the Mint team is over reacting about GTK4 but that's just me.