But nowhere does the page make the claim that we don't know! It only says that it's not a trivial question, and that there was a time that we didn't have a good

But nowhere does the page make the claim that we don't know! It only says that it's not a trivial question, and that there was a time that we didn't have a good explanation for that. Like we used to not have a good explanation for gravity or illnesses or earthquakes or what have you. It gives the best explanation that we have which is also overwhelmingly likely to be true given the evidence but of course there's never anything that we can actually prove in science, so in the interest of pedagogy it doesn't outright say that we know. Anyway, as I said, the page is from 2002 and many things have happened in cosmology since then. Indeed there are things that we didn't know back then but are now pretty sure about.