Look, I've moderated website forums before, and in my experience, it goes like this:
Nobody really does care that much about off topic conversations. We do care about people spewing hatred against others online, because it's degrading and who wants to host an online service filled with angry people lashing out at each other? (Well, maybe Riot Games and Blizzard do, but those are exceptions). So in order to prevent people venting at you for deleting their posts, we can just say "oh hey look it was off topic so I took it down", which is kind of a neat way to avoid conflict. And yes, eventually a mod will come and take down an off-topic conversation if it drags on for too long, but it isn't necessary to do so, strictly speaking, it tends to be more of an aesthetic decision by each moderator.
So, in my humble opinion, I'd say you shouldn't really bother about other people talking off-topic. You can move the conversation back on-topic if you'd like, and just let the mods do their work about the other stuff. ;)
last edited at Sep 30, 2019 7:14PM