Well i lack a certian amount of empathy that most people have so that might explain a bit haha jk jk in all seriousness. we have three choices
1 test products on animals
2 test products on humans
3 dont test and whatever happens to the humans happens
its your choice
We can always try to explore and develop new methods that don't have to necessarily cause intentional harm to any human or animal, or something to at least minimise the usuage of animals.
But point 3, is what pushes and advocates the use of animals.

We do test on humans anyway, its justifying the testing on any form of higher living being.
Its a good thing but a bad business.