I think that's a bit misplaced, as millenials are in their 40's now, so they probably don't just throw things away like you assume. But also...
I used to live out in the woods and had to haul my garbage to the dump every few months. (I didn't want to burn plastic, like some of my crazy neighbors did.)
The city dump changes seasonally. After Christmas, there are piles of old toys that were replaced. After summer, there are hundreds of discarded blue-plastic kid pools. After fall there is a TON of furniture. I have no idea why: do people buy more furniture in the fall in preparation for holidays?
Anyway, I see more cheap furniture from Target and department stores than I do IKEA. Ikea is inexpensive furniture, but vastly better than Walmart, Target, Sam's Club, etc. So I didn't see a lot of IKEA at the dump.