How big is Amazon in the US?

This sub is consistently full of "unsubscribed from amazon" and "Amazon owns x y and z" which is totally fine and in the spirit of anti-consumption. As a northern european though I must ask, how big IS Amazon in the US that it warrants this amount of attention? Like I realize it's a megacorporation (duh) but I have no sense of scale for it. No one I know orders anything from Amazon voluntarily because shipping costs so much up here and takes forever. None of the listed owned by amazon companies are familiar to me at all aside from Audible and Kindle, which I only know from it being promoted by English-speaking YouTubers. I've heard people seriously order a lot of stuff from Amazon, like toilet paper? Food? Is that true? And if it is, why? Won't the shipping costs add up? Why is it so prevalent there? Obviously people order online up here too but I think its more common to drive to the store to buy whatever you need and only order online if you cannot find it anywhere else because.. why would you otherwise? I'm not claiming at all that Nordics are in some way better for this, we are incredibly wasteful and have a huge overconsumption problem as well (don't even get me started on the AliExpress dropship stores). Anyhow, could the Americans maybe give me a perspective on how big Amazon really is over there and why?