Is it not? I certainly don't know or understand even a fraction of what would be considered established science, but if a credible expert tells me that something is supported by established science I will believe it over something like religious dogma. I consider myself to be a "believer" in science.
Science exists in a perpetual state of being supported or challenged by evidence. If the clergy ("credible expert", Nature) make it impossible to challenge the orthodoxy ("established science") then it _is_ dogma.
By being a "believer" in science as you've laid it out, you aren't believing in science as a process, but science as an institution.
>Science exists in a perpetual state of being supported or challenged by evidence
One problem with that. Some sciences, particularly soft or social sciences cross broadly into culture and "ways of life". There are certain things today that cannot be questioned without getting shouted down or deplatformed. So challenging the current widely held scientific facts can be career ending.
That's why there are quite a few people who don't consider some of such fields sciences. I have half a heart to agree with that stance. That's not to say those fields don't have value, but science is the process of building reproduceable, falsifiable evidence. If you can't do that, then you aren't practicing science.
There's clearly some cache to calling your field a science, because we see it so often. They'll even emulate Sciencey Things to maintain the illusion, but like you say, they don't produce testable, falsifiable models. Political Science is a perfect example of a study that's very far from a real science.
Actual science will accept when it's been proven wrong. Much of we have these days isn't that. And that includes many folks working in what would be considered the hard sciences.
"Believe" is an overloaded word. In one sense, it's simply the content of your mental state. In basic epistemology, Knowledge is defined as "Justified True Belief", i.e. when your mental state matches the actual state of the world for the "right" reasons (this is surprisingly tricky to make formal, see [1])If your head is a memory cell, your beliefs are the actual 0s or 1s inside it.
In other senses, "beliefs" are an identity, and some people like to think theirs are more based on science than others. "Believing" in science amounts to adhering to a broad package of ethical and lifestyle choices that references science to various degrees, their followers believe this gives them more legitimacy than other lifesyles or ethics systems, but the actual degree to which they are justified by science varies enormously.
To take 2 extremes :
(1) Taking a stance against fossil fuel is "believing in science" because (good, credible) science says those increase carbon footprint which in turn disrupts the climate in a huge variety of ways, technically this doesn't necessarily imply to oppose fossil fuel as science doesn't have normative component (science doesn't care - in the strictest sense - if human civilization is destroyed or signficantly harmed), but with only an additional few, normally agreed-upon, assumptions you can get there.
(2) Taking a stance against biological-women-exclusive sports is "believing in science" according to the stance followers because a few studies of shaky foundations and questionable funding says there is no unfair advantage to those who had male puberty, although there are tons of other studies that disagree.
Those who say (loudly) they "believe in science" are usually using "believe" in the non-philosophical sense, and the viewpoints they love to push most are usually (2)-like rather than (1)-like.
There are extremely few things (if any) we can know for certain. Thinking in terms of boolean logic like this appears very primitive to me.
In my opinion, the only rigorous way to improve our knowledge, is to employ Bayes Theorem, and Bayesian thinking in general.
You and I may have different prior on a topic. We may see the same evidence, but end up believing different things because of the prior. As long as we state the prior, that is good and fair. If the evidence contradicts my prior, I should lower the confidence I have in my belief, even if the prior was big enough that I still believe the same thing.
Unfortunately, what often happens, is that people lock themselves into believing things absolutely. If you lock some prior probability to 1, Bayes' Theorem has n way to let you update that belief.
This is especially common when it comes to beliefs related to religion and identity. In fact, this is one way to define religious belief. Anything you believe that you will NOT stop believing regardless of evidence, could be defined as religious.
If you believe in God, and we discover that Heaven is not on the other side of the starts, the believer just modifies non-core parts, and claims that "God is everywhere and nowhere".
If belief in racist oppression is what defines you, and you find that most individuals are not individually racist anymore, you can just introduce "Structural Racism" that claims that hard work, staying married and maths are racist.
So far as I can tell, the Gettier problem is exactly the same as "I believe in Science" - There's a fallacy of false equivalence in "X is a justified argument, X||Y is therefore justified because of the justification in X", or something like that, I'm not sure what to call that fallacy.
When you evaluate the truth of the whole argument, you'll find that it's not a "Justified True Belief" because the truth does not flow through the justified prepositions.
