I think one of the big reasons I don't like libadwaita/GTK3+ is it just clutters up the titlebar with stuff that should be in a menubar and toolbar. With a clear titlebar, I know where to drag the window from, but with stuff in the titlebar, it makes me think for a few seconds, and that's not good design. This is worse with complex stuff like Pinta. That being said, this isn't just a libadwaita/GTK3+ problem: a lot of stuff like on OS X and sometimes Windows has this problem.