Reminds me of various old sayings, such as: "The truth is that which, when you stop believing in it, doesn't go away." And "if you tell the truth, you don't have to remember anything."

I don't necessarily believe in a purely objective reality, personally. I don't know for sure that there is some kind of platonic ideal structure of all things that exists apart from observers and always has and always will, it's a hard thing to figure out how to even start to prove. But there sure does seem like there is one, some kind of underlying pattern to reality that everyone who makes honest rigorous measurements seems to be measuring the same way. So if you just do straightforward science it seems like you automatically end up participating in a single common shared worldview.

Whereas if you just make shit up based on your beliefs, you end up with a worldview that's divergent from everyone else who's also making shit up based on their beliefs.

It gives an inherent advantage to the reality-based people. They end up working together and supporting each other even if they have absolutely no way to communicate with each other. Physicists doing experiments on opposite sides of the planet with no awareness of each other can produce results that, when they're later brought together, click into place as if the two of them had directly collaborated all their lives. It's awesome.