What’d be the benefit of keeping it synchronous comms say vs an email thread?

Some mailing lists are fascinating to read.

I actually had that idea not long ago.

https://news.ycombinator.com/item?id=49307573

Emails take alot longer to send & receive (like 5 to 10 seconds), & they don't automatically show new emails at the bottom (you have to click on the yellow bottomright bar that pops up in Gmail).