Part of what makes TempleOS so powerful with so little code is that everything fits together, so you can make a lot of assumptions. I don't know the details, but I bet there are lots of design choices that work well, or are able to implement concisely specifically because of the resolution assumption.
Really tightly integrated designs eventually get to the point where there's almost nothing to change... No word could be swapped, no color could be different, because the each design choice relies on the last. Many designers use that as a measure of when something is ready. When you really apply iterative design practices, you add and take away and add and take away, and you eventually end up with an extremely lightweight design that is very strong, but where every piece of the whole is extremely important. Apple strives for this.
I'm not saying TempleOS is there, but that's the kind of design project it is, and that's where it's headed. That's what makes it "holy"... It's not perfect but it's pointed at perfection and it aims to get there. Linus, in contrast, doesn't care if Linux is perfect. He wants to make something that's useful and is willing to make a mess if it helps people get their work done.