When you feel a question burbling up and you want to ask it, stop for a moment and determine:
What will you do with the answer when you get it?
For example, you might "feel better because now I understand something that was confusing me." Or you might "tell the person they can stop telling me step-by-step because I actually know how to make a peanut butter sandwich." Or you might "tell them they are wrong to be doing that thing for that reason and get started on convincing them to change."
You seem to see these as all the same thing, but they're not. Thing 1 is fine, though curiosity and a desire not to be confused may be more valuable to you than to other people, and the interruption for the question may be an irritant. Thing 2 is sometimes fine and sometimes not, maybe this team makes pb sandwiches their own special way and therefore wants to give you all the steps even when you think it isn't needed. Thing 3 is exhausting in a way I don't think you understand at all, so I'm going to elaborate.
Companies exist for a long time. Their assets, like software, exist for a long time, generally longer than the teams that work on them. Process and procedure does the same. Sometimes, these things become out of date. They aren't as good as some other options that exist. When that happens, people look at them and evaluate whether to update or not. Sometimes, they update. Sometimes, they don't. They accept something suboptimal. It might be because the distance from optimum is very small. It might be because there is no time to update, or no-one available who can do it. It might be because they know updating carries its own risks and could make things worse, not better. Whatever, they look into it and they make a choice. They probably revisit the decision semi regularly. Maybe once a year someone says "do we still need that XP machine?" or "should we move the flagship product to another language or framework?" or the like. And people gather a pile of information and make a choice. Maybe they will finally be getting rid of that thing in a year or two. Maybe an upgrade project is bubbling on someone's back burner. Maybe that business line will shut down soon. Whatever. Things are under control.
And then a new person shows up and just keeps picking and poking. Why is this like that? And then some really non-neutral questions, questions that arrive with a giant dose of judgement and scorn like "what software is so important that we keep XP on the network just to use it?" where it's clear, you think these people need to answer to you and to justify their choices to you. When you don't know the story or the reasons at all. You can say you're asking trying to get the story, but the way you're asking carries all kinds of judgement you can't make until you know the story.
And you know, when I've been part of teams that have a suboptimal part, we know it's suboptimal, we wish we could fix it, but money isn't free and time isn't free and Judgemental New Person demanding an explanation as though I answer to them ... I just want it to stop.
So, practical advice. Ask all the "thing 1" questions you want. If some of it is just idle curiosity then say so. "Is there like some sort of weird historical reason for how people got assigned to one of the two locations?". Be cautious with "thing 2" questions. They can carry an "I'm smarter than you're treating me" tone and also risk you doing things wrong because you told someone you didn't need to be shown how to do them. And just stop doing "thing 3" questions forever, unless the person directly reports to you, and even then do them very gently.
In your particular situation, where you have asked at least one "thing 3" question, some people may now kind of cringe when you ask anything, wondering if this is the opening to a lecture about how they're doing it wrong and should adopt some solution that you can tell instantly will be so much better and totally worth adopting. This may make people on edge and reluctant to discuss simple things like who works in which location, worried they are going to be pestered to change an arrangement they're not responsible for.