The thread was created in October 2017 after 7 years since the last comment, people have only recently started commenting. I think it would be convenient to lock that kind of thread and if someone thinks it would be interesting to comment on something similar they can open a thread, 7 years later (although in the specific case of that thread I think it would be fine to be trashed as the OP is low value and has quite a few comments of that style).
You are right, topics like these should be locked but not trashed as they are already counted in the forum stats as well, and things need a little dusting here on this forum so, the mods, or admin might not prefer to delete the old topics instead locking them would be a better decision. I also saw many old topics and the frustrating thing is to know the dates of the topics, I have to open them and then close them after seeing the dates, I wonder if anyone else is facing the same issue.
Well besides locking topics like these, it would be best that we are given an extra feature that would tell us when this topic is made, instead of the last post made on that topic, or is there any way to do that already and I'm not aware of that. Then do let me know. People actually don't really see when the topics was made, or either the OP is active or not, they just see the last post and started to make posts there. I might have also made some posts on such thread also.