Scientist... believes... something here doesn’t add up. In science either you have evidence or you’re just bullshitting.
We don't "believe" in scientific concepts. Their being a fact has no precondition on whether (or how many) people believe in them. Evolution didn't begin when Darwin started studying it.
That being said, you're right. We have to start somewhere. For example, scientists just a hundred or so years ago believed in the existence of something called aether. I believe many (most?) scientists will change their opinion if we can provide them evidence contrary to their belief. See https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_exper...
On the other hand, scientists are just human as well and are subject to the same flaws and limitations as the rest of us. Facts are only facts, until they are not (that sounded weird, I am not actually against evidence based decision-making). I mean we make what we think is our best attempt at describing our world given the tools we have and the reality we live in. I wouldn't put too much weight that scientists believe aging is optional any more than I'd put weight on scientists saying technically it is possible for us to fly in a metal tube across the Atlantic Ocean or that technically we can put a man on the moon... until it happens.
I don’t understand the point you’re making here. Surely your second sentence contradicts the first?
I rarely have a point to make. I started off thinking I disagree with the parent comment but as I started typing I realized I agree with them more than not. It is more of a thinking out loud. It helps me a lot because I have very simplistic opinions that are sometimes VERY incorrect so when I think out loud, people can correct me. I guess where I thought I differed from the parent is that when you "believe" in something, you will dig into your position given contrary evidence. I like to believe this is not true with scientists.