Huh. Different instances, I guess. I generally don’t browse by all, but on my feed most news were non-US (mostly Europe although quite a few about Asia as well). But then again my instance is pretty tiny and definitely isn’t federated with most large communities, so my perspective might be skewed.
To get a better view of the general content on Lemmy maybe we should look at the all feeds of lemm.ee or lemmy.world which, now that I look at them, are indeed quite US centric. So I guess it was just my perspective.