When you submit a report for a post or comment from another instance, it gets sent to us as well as that instance’s admins and the relevant community mods. Unless the content is particularly heinous, we usually just mark the reports as resolved and leave the decisions to that instance’s admins or that community’s mods. E.g. if you visit other instances, you’re likely going to find someone both-sidesing the genocide in Gaza out of ignorance, and I personally prefer (other admins might disagree) not to ban them for something they posted on another instance (again, unless it’s particularly heinous, e.g. cheering for “Israel”) since they may eventually come across Lemmygrad and learn something.
Basically, just keep in mind that reporting content from another instance will usually be ignored by us, so it’s typically only worth it if it’s against the rules of that instance or community