Sounds like banishing it into the abyss. I use StackExchange a lot, and this thread is the first time I've heard it has a "chat system".

The chat system had been around for a long time. It was introduced by Jeff with the blog post https://stackoverflow.blog/2010/04/29/do-trilogy-sites-need-...

Question tangent comments get sent there to try to keep the focus on Q&A rather than side back and forth. It's not gone permanently.

There are also persistent chat rooms for various topics. Their archives are easily searchable.