Plenty of software from that vintage works better than modern equivalents.

UX is about more than how something looks visually - equally (or more) important is how it behaves, how the user interacts with it, and how it gets out of your way and lets you do your actual work (or doesn't)

I don't disagree.

But it's the author who is implying that "legacy = bad"

Note: I genuinely love Windows 2000 UI/UX (and wish it still existed today)

I think it's a perfect little detail that captures this writer's persona. Their blog is powered by the (once famed, and very popular) Octopress [0]. Every developer was running their own blog off of it.

My point is, it looks like the author found something that works... for over a decade and well. They wish GitHub would 'just work'

0: http://octopress.org/

I don't think that the design is that old. I was working as a web designed ~11 years back and a lot of these design ideas were "in" back then. The subtle dark and light 1px lines that create this embedded effect, some shadows around certain elements, not a completely trivial typography. This is a 2010-2014 type of design.

The blog is literally built using unsupported software (Octopress). I don't think it's been updated since 2016.