How to finding life in extreme environment on earth support the idea that life exists elsewhere?

Very often the critics of the idea that there's life on other planets tend to argue that in order for the life to develop there has to be certain right conditions, like water, temperature that is not extreme, oxygen etc. But with the greater examinations of the most extreme places on the planet, it has been shown and proved that life can exist in places that were never thought it is possible, in fact, the only places on the planet where there's no life is inside the volcanoes. Organisms have been discovered that live at places where there's no oxygen, deep bellow the ice, at temperatures that are significantly higher than those on the surface of Earth, or at places where there's no water. This proves and supports the idea that life is able to find its way to survive in incredibly cruel environments, so there's no reason why it would not be able to develop on other planets or moons in the universe.