About the narrower column, it was this issue, and inspired by Oasis's layout: https://gitlab.com/staltz/manyverse/-/issues/1689

The reasoning is two fold:

• Typography: lines shouldn't be too long otherwise it negatively affects how much your eyes need to work to find the continuation, example article
• If the middle column is too wide, image previews (with the "fading to white" preview) show just a very tiny percentage of the image, basically convey little to no information to "preview" it

I guess there is additional tweaking we could do, like maybe make a bit wider, and each Thread "card" taller too. But we're trying to avoid the percentage-based width because it can create extremely wide thread cards and that's bad.