Seems the modern corollary to the demoscene is TouchDesigner programming. I always thought it would be such a neat thing for demosceners to jump to TD and work with other forms of art like live dance and live music. The fact you can have body tracking, hand gesture recognition and also have it react to sound seems like the next step in demoscene stuff.
A lot of recent demos use https://www.notch.one/ or https://github.com/tixl3d/tixl
More https://github.com/psykon/awesome-demoscene
Yeah, I remember reading an interview with one of the few big demosceners, and they said that to compete in the highest leagues, you need editing tools to build these impressive scenes.
After all the most talented musicians and visual designers often were not the same people, and every artistic pursuit involves a lot of iteration.
To be fair groups tended to build the tools themselves, not to take away from their achievements, but once the tools are done and public (like the ones you shared), a lot of the challenge and point of competition is gone.
Tooling also tends to create a moat between 'users' and 'developers', the former of which lack the low-level knowledge to transition into the latter.