"The people of Sweden"
I don't know what word class Zweedse is in Dutch (I know zero Dutch) but it looks more like an adjective than a noun?
If we use an adjective instead, we can say both det svenska folket and svenska folket. It's unclear to me why we can say svenska folket without an article: I usually tell people this occurs with 1) things that function as names 2) with numerals and similar adjectives. It clearly isn't #2, but maybe 'svenska folket' has been used so much it's gotten close to #1 after all.
Oh yeah, sorry, I got a bit confused. It is an adjective in Dutch: because I'm used to the way Dutch handles this, I think my head likes to think that "Sveriges" is an adjective also - but of course, it isn't.
That's very interesting, thanks for replying in such detail! You seem like a really great person and language lover :).