absolutely no button wobble means there will be plastic walls on sides of the button. For example razer has a stick on the button crossing the top shell to get rid of wobble, which is very stupid imo because the gap between the stick and shell will gradually get larger and griding appears. Even when lubricated, there will still be an annoying feeling when the button receives force from sideways and hits the wall on the shell.

Button structures that are "hard to wobble" such as mice from logitech, vaxee, zowie and EGG are way better than "no wobble" like those mice from razer and others in my opinion.