The first time information you need is sent in a thread that started a week ago and that you're not already on, you'll get why folks don't like Slack threads. They're an anti-feature, IMO.
If Slack offered a way to show all messages whether or not they're in a thread, as they come in, I'd be down. I wouldn't like 'em but at least I could work around their fundamental flaws.
But what it really needs is elevating threads to something like a temporary "sub-channel". Show them on the side-bar just like channels so you don't lose messsages CONSTANTLY if you're in more than 1 active thread at a time.
Usually, in our workspace, it's the person leading the discussion that at some points decide to redirect the talk somewhere else
Maybe it's a company size thing, as mentioned elsewhere in this discussion. At my size company (<10 people), every thread I'm watching - I pretty much need to see all of the new messages.
This is how Zulip works. It's extremely effective.
Basically, a thread is visible at a first glance from the UI, while that's not true in Slack. Also, you can kinda replicate Zulip structure by just using channels with naming conventions, so you have: - generic channels, e.g. for status update for many stakeholders - specific channels for each feature - threads in each channel where you discuss a single point