Thanos is a powerful being. He gathered all six infinity stones to wipe out half of the living beings across all galaxies. He thinks he’s doing the right thing, he believed that planets will eventually be too small. The people on the planet will suffer from starving and overpopulation. When he finally succeeded, it wasn’t a good ending for either him or anyone else.
But even if it is true, scientists believe that it won’t be harmful to humans. Even though Thanos wiped out half of our main source of food, the useful things in our body like microscopic organisms, or microbes. Scientists claim that there are billions of cells in our body losing half of them shouldn’t be the problem.