One reason we added threaded comments is that, regardless of intent or active moderation, we know from other sites that comments will sometimes be used for discussions. Sometimes those discussions are worth keeping (as background for an edit, for instance, or to alert people who would otherwise start that discussion already that it's been done). Somewhere Else realized that just deleting them didn't work either and added "move to chat". Codidact took a different approach: comments aren't nearly as invasive if they're threaded and collapsible (by thread). So that 15-comment discussion about gdb can happen over there without preventing you from asking the author which version of C++ the code is written for.

Threading seems like a useful compromise but I must say it is intrusive here when you have to leave the question page to read or engage in the comments. Punitive irritation is not the way to get people to respect a system. People are quite familiar with threading systems and the normal user interface means when you locate and click on the expand button the thread expands a level. While writing this comment I am unable to view the post I am commenting on <<<<<< Sorry I went to check what level of effort is required and found an expand arrow for the question and answer I would love it if there was a USER setting that would not collapse stuff that has been open unless I ask it to. This is not MacOS this is a user friendly site that leaves the visitor in control of their destiny hopefully.

As seen on other sites, it is useful to consider what visitors want (as in what they commonly do) rather than insist the UI will be dictated as a result of profit calculations from A/B testing.