@Riger The Spirit Bomb / Genkidama did have 1-2 non-Canon kills from the movies aside from Majin Buu. Otherwise you're pretty much right that every other opponent survived taking it. Theoretically Buu would've survived as well but Goku got his energy "wished full" while firing it.
I love that Garou's motivation is to simply unite humanity by being the threat they have to band together to beat but will probably still fail to. However that way they will still be scared together instead of discriminating against one another. At least that's what I took from the chapter.
For the people wondering: I think the no techniques applies to the magic-like stuff some of them can do instead of applying their style to the way they try to do the tests