I'm quite confused because almost all conversation in my company's slack happens in threads. Maybe your impression of Slack was formed in a time when they didn't have threads?
It has "private" group chats in Chats tab and all meetings auto-create group chats. At various points I've tried to push conversations into a proper Team and threaded chat, but the "convenience" of just sending a chat message in last week's meeting chat or some hand-built group chat rather than just finding the right Team channel seems to keep winning out more often than not.
I think they’re just saying that teams forces you into using a thread, and make a choice to create a new one if that’s what you want. In slack by default you’re writing a top level message (ie creating a new thread)
Indeed, never underestimate the power of defaults. There’s a tendency on HN to say “well, everyone should just use threads on Slack then.” There is, of course, a way Slack could make that happen: make it the default.
(For what it’s worth, I much prefer Slack for communicating, but when I have to find something, I wish I were looking for it in Teams.)
Pedantic perhaps but maybe it's worth pointing out that Teams doesn't force you to use a thread. It just makes it the obvious choice since each top level message has a reply button directly on it so it's a single step process. Also when we're talking about Teams there's a big distinction between a Teams/Teams/Channel vs a Teams/Chat which is its own annoyance. They don't even support the same formatting capabilities (e.g. markdown) which is weird.
Slacks threading model is super weak compared to other options. I haven’t used teams, but I went from Zulip to Slack a little while ago and it felt like a huge step backwards.
Regarding threads I've seen two options (besides zulip state of the art handling of that). Either hide the threads like slack or throw them in your face like Cisco webex teams.