It seems beautiful, but saying unparalleled is a little hyperbolic. Western Norway, Switzerland, Northern Scotland, and the North American Rockies all appeal to similar sensibilities and arguably just as grand, if not more so in some cases.
There are no trees in Iceland. It's fine to look at for a week and the northern lights are a novelty, but the US and Canada (even California alone) offer much much more in terms of nature.
There are definitely trees in Iceland. Not many, not everywhere, and not impressive ones, but they exist.
However if you've been to Iceland and thought there wasn't much outdoors, I'm not really sure what to say. It's sparsely inhabited, beautiful, and gigantic. It's a totally different experience from something like the sierras.
Not all nomads are cheap / poor. I know there is a stereotype (probably well earned) about nomads. It's why you see low COL places being so popular (Thailand, Bali, Portugal, Mexico, etc). They get the most attention, but there's definitely folks who make good money and have interests in different regions/climates/activities. I can definitely see the appeal of Iceland. It's gorgeous natural landscape. I didn't get to see the northern lights while there, doing a six month stay might increase those chances tremendously versus flying over and crossing my fingers. I doubt we will see a huge flood to Iceland, but offering this kind of visa makes it easier for some higher value, longer term visitors. That's good for their economy and if they make it easy enough the administrative hurdles aren't that high, even better.
Korea is a fantastic place to live. The food is amazing, the country itself is beautiful, and the people are very welcoming (at least when I was there about a decade ago). The only issue is that outside of Seoul not a lot of people speak English, so you would need to learn a bit of basic Korean.
Its basically an urbanist's dream come true, with mega tall apartment complexes even in backwater villages. Right next to single family homes, right next to hilly forested areas where you can hike. There is excellent transit so you don't need to own a car (although a lot of people still do).
There is the possibility of being caught in a nuclear hellfire though. So... YMMV.
They closed a month ago due to Omicron, a measure multiple sensible countries followed to reduce risk. The intent is to remove this restriction at the end of Feb.
The only problem would be the time difference, assuming you're working for an American company.
I've spent 4 months in Japan as a digital nomad, while working for a company based in Europe. It worked. Now that I live and work in the US, I'm pretty sure the time difference would be too disruptive.