Threadless is superior, no argument there.

Whether people need that benefit is debatable.

Scozim's bike is not an example of threaded vs threadless. It's threaded vs threaded (with an adapter). The adapater route, does not really add a benefit except for ease of changing bars and using modern bars. If he had a true threadless setup, I think he could make it look pretty damn good. That said, if he used spacers under the adapater to hide the neck and taper of the adapter, his setup could look a lot better.

If you have a bike that you already have the original fork for, use whatever system the bike came with. It would be silly to take a threadless fork, add threads, and cut it to (IMO) downgrade. Quill stems are nicer to look at, but you can make a threadless setup look pretty damn good. Use a 17 degree stem flipped so it is parallel with your TT, no less than 90mm (less would be a poor fit), no more than 30mm spacers under the stem, spacers to match the stem. Of course, there are other and similar conventions to using a quill stem.

Different strokes for different folks. If I was building a frame up without the fork, I'd go threadless for sure.