As it was explained to me by my LBS, there was (and probably still is) a backlog on shipping. Most of the stuff is sitting in the shipyards waiting to be put on a boat. Manufacturers can't make anymore because they have nowhere to put it until it can be shipped. COVID restrictions keep the boats from exporting. And domestically (at least in the US), all the postal carriers are underfunded and overworked.

And that's not including weather and other unforeseen hiccups (ie stuck boats)