Outside the field, but generally acquainted with scientific studies of things much closer and easier to study: I wonder how much guesswork really goes into astrophysics vs other areas?
Guesswork is part of forming a hypothesis, as it is with any science. The thing about astrophysics is that it's very hard (or impossible) to conduct an experiment to prove a hypothesis, and with very few exceptions it's impossible to see something happening in real time.
What you do have is a vast amount of data in the obseravable universe. So for a theory to be valid, it needs to not contradict all that out there which we can see. Or if it does contradict it, it needs to explain why that is and not contradict other things.
Often, as with particle physics, we're limited by what we can see, so we need new technologies (such as the JWST) to give us greater insights. Just as with modern particle physics, in a lot of cases this helps to reduce the size of error bars in observations or hypotheses, which then helps to reduce the problem space and weed out theories that then fall out of these error bars.
This is why you can have several competing theories at once (for example, various alternatives to dark matter). Some may be more popular than others, or may be more likely than others, but they stay on the table until actually disproven[1].
(Have an astrophysics degree, not a professional astrophysicist)
[1] Although as far as I was aware, Tired Light was actually considered off the table.
Maybe it's a messaging problem. Even for that article, the headline appears more decisive every time it's repeated. How long until it appears in mass media as "Science wrong again?"
