Disney made many technological breakthroughs that allowed for things like parallax layers, glow and other effects, and compositing without green screens back in

Disney made many technological breakthroughs that allowed for things like parallax layers, glow and other effects, and compositing without green screens back in the days when everything had to be done in-camera. But the use of the techniques those technological breakthroughs allowed is entirely possible without that specific technology, and in fact can be done much easier nowadays with computers.