They are limited to 1 hour. You have 2 or more parties giving opening questions. And the 9 justices questioning each on what are often thousands of pages of documents.
It is really more of an opportunity to publicly critique each side with a few pointed questions.
There have been cases where it really sounded like there was a traditional split along the court and then some questions pop up and the answers are so bad / arguments clearly absurd / the lawyers have no good answers that suddenly the case is clearly going one way.
Usually this revolves around the sort of second order effects of a potential ruling and where ideology isn't entirely clear / has some conflicts with those second order effects.
In fact, I think it would be a bad thing if the court swung on oral arguments. These are very complex topics prepared by an army of lawyers on each side. They should not hinge on if a single presenter doesn't have a clear an concise answer within two seconds of being asked it.
As for the rulings there's A LOT more than ruling one way or another, the ruling itself can range in all sorts of directions.
I ask a specific enough question from someone I don't typically talk to, that I know has a non controversial answer. They answer it and it shows I'm thinking of nuts and bolts and how things work and everyone moves on.
You'd be surprised how many folks think "oh this guy knows all about / is really thinking about that thing to ask that kind of specific question".
Just a quick one like that works well. You do have to know the room and the situation to avoid falling into some messes but it works.
I'm not saying never say anything if something important and relevant is being missed, but in my experience that rarely happens.
I've sat in a meeting and had everyone ask my questions anyway, better to let them do it. Sometimes I learn more that way.
Not everyone operates in a 'let's hash this out verbally' manner, perhaps they do even less so in a crowd of folks already doing that.
Granted I often find Thomas's opinions kinda absurd... so I'm talking more generally about "not talking" and less so about Thomas. I just wouldn't hold 'not talking' against anyone. Different people operate differently.