Some of the oldest web forums (circa '98) I've been to use the nested comment format you see on Reddit or on here. The flat timeline format because much more popular from what I've seen.
Reddit style forums are not great for posts intended to log something in progress (like a computer build) because they require the user to make a new thread multiple times instead of making a new comment that automatically brings the thread back to the first page. But flat list threads are great for that.
They usually try to compromise with comment replies shown in "comment pyramids" but they can get unwieldy quick. It's a reasonable tradeoff for the flat chronological layout.
It's more than a concept. They already exist right now. Amazon has a returnship program for example. "Return to Work" is another name given to them.
I'm interested in how to find them more easily, and from smaller companies. Finding them in general is like a needle in a haystack (as well as discussions about them, apparently)
I stumbled into it by accident as a junior software engineer. They offered me a 3-month contract-to-hire job, but instead it became a 2-year independent contractor job for the company. Most jobs that followed have been cold applying to startup contract jobs from Craigslist or obtaining them from local word-of-mouth. It's very feast or famine, and not everyone can keep the momentum of new clients going. As for myself, I am planning to leave self-employed work for the first time in over a decade, for the relative safety of a full-time job (even with the current market situation).
And this is the only top level reply. Interesting.