The format on here isn't really suited to multiple responses, imo, but you should look at a website called Kialo. I haven't used it in years and I don't know if it's active but it's an interesting concept based very much on that idea, with the aim of making discussions more formal and rigorous.
Here's an example of what it looks like, for the discussion topic Should American Football Be Banned?
The first circle shows top level positions that one might take, one of which I've selected, suggesting it should be reformed rather than banned. Coming out from that are points in favor or against, like, "It is not possible to reform American football to make it safe enough to play," and then from that point there's more points, one saying that risk of brain injury is unavoidable and another pointing out health risks that could be addressed, like heat illness.
spoiler It's also possible to view the discussion in a different format, like so:
:::
Clicking on any of those points will let you see the replies.
New comments have to be approved and they have to be meaningfully different from things that have already been posted, and they're supposed to be limited to a single point.
And you can comment on points suggesting clarification
It's a pretty different format and vibe compared to what we have here, but even if it's not something you're into, I think it's an interesting little experiment. Imo, you would need something formatted that way for the multiple comment approach to work well and be readable.