Looking at it the other way, Black 4.0 reflects 0.05% of the light, and Vantablack 0.035%. So Black 4.0 reflects about 40% more light. The difference is not that small.

On the other hand, Vantablack is highly toxic (similar to asbestos), while Black 4.0 should be quite a lot safer.

No. These numbers are measured perpendicular.

Vanta Black has low total hemispherical reflectance below 1% from all angles, others don't.

See: https://en.wikipedia.org/wiki/Anish_Kapoor#Vantablack_contro...

It's a reaction to Anish Kapoor's exclusive licensing of Vantablack, regarded as abusive in the art world.

Having seen his exhibit in Venice. I will say, in the right contexts it really does look like a black hole. This doesn’t require limited lighting, just regular room lighting. 3d objects painted with it will disappear into themselves as if it was 2d.