LLM-written clones of free software into proprietary seem to be a growing trend now.
With manim, it's probably legal (I think MIT license?), but in general, it makes the world a worse place.
All we want to do is innovate. We simply can't open source this because we're rewriting and rebuilding it every day.
It's the AI frontier ethos. "I get mine." That's the culture now.
Speaking of which, it happened before, too, in the 1970's with personal computer software.