You said:
> Sweden had to go back on it
They did not. If your standard for "going back on it" is "adding some restrictions", then you are erecting a straw man argument. By this standard, every country in Europe "had to go back on it", as all of them changed their tactics over time.
Also, not incidentally: I'm aware of no legitimate source for the claim that Sweden's hospitals were "full" (which is a non-specific claim). Most sources I've read emphasized that hospitals were under stress -- like in most parts of the Europe -- with some hospitals closer than others to capacity, and resources being shifted around the nation to manage:
https://www.thelocal.se/20201211/is-the-second-wave-overload...
Again, you could take this article and put it in Paris, Berlin, London, Brussels or other major cities in Europe in December of 2020. Details matter, and vague claims that "hospitals are full" are meaningless.