The disconnect between your post and parent is due to time-lapse. In the very early 70s (arguably the peak of punk as a creative force in the UK), yes, there was little or no broadcasting tech - punk disseminated slowly through live gigs and low-volume magazines in the UK. By the time it had gained significant cultural and commercial force though, particularly outside Britain, the tech mentioned had arrived. The peak of creative punk in continental Europe and US (outside NY) is arguably late 70s/early 80s. Culture transmission, back then, was slow.

So you're both somewhat correct. The birth of punk was not about tech, but about self-reliance: doing your own thing, no matter how ugly or discordant (see early punk bands and their notoriously bad vocalists), fuck everyone else. It was the application of flower-power principles to urban energy-crisis nihilism. As punk grew, a generation of democratized technology appeared that could support and supercharge such ethos, to the point that (if you were not part of the original hardcore nucleus) you could easily assume the tech was indivisible from the ethos and necessary to its survival.