God I only took a peek at the screenshots and I want that environment so bad. I miss it. I realise what it makes me sound like, sitting on my M2 32GB 1TB monster. Nostalgia hits you in the feels.
I'd say it's a lot more than _just_ nostalgia, though that certainly can play in too... But there are plenty of aspects of this, like snappy interaction latencies and a small pool of simple but consistent UI components that behave the same every time you see them, that I think are objectively better than much of what we see today. There was absolutely something lost in consistency and quality when we resigned ourselves to most UIs starting with a blank HTML DOM and building their own custom UI from scratch.