For example, I'm using Debian, and I think we could learn a thing or two from Mint about how to make it "friendlier" for new users. I often see Mint recommended to new users, but rarely Debian, which has a goal to be "the universal operating system".
I also think we could learn website design from.. looks at notes ..everyone else.
The Debian website is trash and I'm glad to see it acknowledged. People always take criticism of the website as if folks are saying it looks ugly. No. The layout is just icky.