I agree - taskbar on the side is the best layout. It's very common on Macs and you can do it in Windows 10 now too.
The problem with Unity was that it was buggy as hell, and the launcher was really badly styled. Huge gaps between icons, the search filter was unusable, etc.
That's hardly innovation though since most DEs over the past 2+ decades that I can think of would let you move the taskbar (if they had one) anyway.