I don’t think it’s wasteful to have both KDE and Gnome. It’s healthy competition and as you say, innovation.
However the job of a distribution is to gather upstream software into a meaningful OS, and rewriting everything that should be an upstream software shared with other distributions is a distraction.
So Unity was unnecessary “not invented here” syndrome. Just like Snap is.
I just don’t like Linus because he’s annoying and abuses clickbait thumbnails and titles.
Some of their videos (from other people than himself) are good, but usually I’ll avoid LTT content all together.
For that reason I’m not really sure what happened, and I don’t really care.