Older James Blake is more "typical" style dubstep.
And dub is not dubstep, no. It's not punk either. It's was originally a subgenre of reggae pioneered by the likes of King Tubby in the 60s and 70s. In part dubstep grew out of the fusion of dub with UK 2-step garage, though it also owes a lot to Basic Channel who pioneered a sort of "dub techno" which isn't exactly dubstep, and in fact I'd say predates it. They later went on to become more overtly dub with their Rhythm & Sound project, while others like Monolake continued their earlier trajectory and took it in new directions with the Chain Reaction label.
In my humble opinion generally: dub techno > dubstep.