Actually, the right looks like a Kallax, which are probably the sturdiest item in their catalogue given the walls are like 3cm (1.2 in) thick. I've taken them apart and reassembled them before, and unlike every other piece of Ikea furniture I've done that to, they're actually just as stable and reliable as before.

Ikea’s stuff is fine for the price you pay. Oddly enough their solid pine items are really sturdy and usually among the cheapest since it’s so simple and comes unfinished. I have a Tarva queen sized bed and it’s great, plus I bought $8 of 2x2 and made custom length legs for it.

The one on the left wasn’t necessarily built to last longer. It was probably absurdly expensive back in the day and there were plenty of more cheaply made(but admittedly solid wood) options. No one is taking pictures of those less flashy pieces, though. Also you say timeless but, c’mon, it’s cool and all but definitely doesn’t fit everywhere. It screams “medieval castle” and is pretty over-the-top for basically any modern home, even grandma’s place.

The other thing about those shelves is that they’re a lot lighter than solid wood. When you want to place them in fun locations and need to use drywall anchors it’s a big thing to reduce the weight where you can. It’s not like people are displaying bowlingballs in them. They last a plenty long time unless you have a habit of trashing your place and there’s certainly such a thing as “over-built”. If that shelf “inevitably falls out of style” then style moves slower than I thought because they’ve been making and selling that thing for-fuckin’-ever. Most importantly it’s affordable in today’s world where executives have siphoned away all our money and the working class has been left without the funds to invest in quality furniture when the Ikea stuff does just fine.

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TL;DR the piece on the left was not common when it was made and the piece on the right has its merits, not least of which is accessibility.

I have some ikea pieces that I bought when I started grad school. They're 10 years old, have been through 4 moves, and they're still doing fine. Even better, I could move them myself without it being a huge strain. They aren't high quality (which tends to seem to mean heavy and not disassemblable), but they've treated me pretty well.

Yes, that is part of the joke.