Forum:Conversations across two user talk pages

I'm curious: why do most "User talk" discussions take place on two pages simultaneously? E.g. Fred posts on Sally's talk page; instead of replying directly Sally posts her response on Fred's talk page; he responds again on hers (threading as a reply to his initial post), etc, etc. Is there a reason this emerged as a convention, rather than just keeping the discussion where it originated? It makes reading an entire conversation ...rather trying, when you might want to for reference. Starkidsoph ☎  01:23, 28 June 2023 (UTC)

Discussion
Not sure if there is any actual reason why, but I find it very confusing to deal with. I also find it very telling that this is some random thing this Wiki made up as when you get Fandon employees use the talk pages on this Wiki, they don't do this bizarre practice (and the same is true across other Wikis. I'm all for changing it TBH. 01:27, 28 June 2023 (UTC)