They did that back in the reel to reel tape days too...it was just destructive. Songs could have tons of layers, but they had to bounce tracks down to stay within track limits for the final mix.

Queen's music is a massive pile of overdubs, especially for vocals and guitar. The Beatles also, and they were heavily into looping (physically cutting audio tape and gluing it in a loop, then re-recording it). Vocal and guitar double-tracking has also been the norm since the 50s, at least.

80s pop was also generally full of synthesizer stacks, where MIDI from one keyboard was simultaneously triggering several synths to create layers.