I agree completely. Then there's cases like colored stones cut into radiants, and hearts--how do you even talk about the light performance of a perfect pink heart?The modern ideal cut is a good to great all around cut in a variety of lighting but it is not the best in every kind of lighting.
It is not hard to say design a princess cut that in bright direct lighting and by some metrics that is brighter than a modern ideal cut.
An oec and some step cuts can be brighter in soft and diffused lighting while being close with them in most lighting.
In off axis lighting a well cut step cut, pear or oval can make them look a little anemic.
So one and so forth.