A few hours later another programmer came up with the prototype of a much faster terminal renderer, proving that for an experienced programmer a terminal renderer is a fun weekend project and far away from being a multiyear long research undertaking.

I have no idea if this is the case here, and I suspect it might not be, but pretty much every time I've seen a developer complain that something is slow and then 'prove' that it can be faster by making a proof-of-concept the only reason theirs is faster is because it doesn't implement the important-but-slow bits and it ignores most of the edge cases. You shouldn't automatically assume something is actually bad just because someone shows a better proof-of-concept 'alternative'. They may have just ignored half the stuff it needs to do.