You’re right that science doesn’t ever really prove anything per se. The best it can do is come up with a useful model that we can use to make predictions. The neat part is that this is extremely practical. You can take prediction X and apply it in the real world, so you don’t have to take someone at face value. For example, you know the theory of electromagnetism is more or less accurate because we have phones that extensively use those principles. And if that isn’t sufficient evidence, the present year is literally the best year ever for you to most easily test the theory yourself.