I bought a simple square pine table (I think it's 'Ingo') for maybe C$50 about 15 years ago. We used it as a dining table for a few years, then when we moved and bought a fancier marble tulip table it was shuffled out to the balcony to be patio furniture. We did a longer move across the country and almost got rid of it but it's easy to disassemble with just 1 angled bolt for each leg so I kept it for an extra work table for odd jobs. The top has been used as a sacrificial surface for drilling and hundreds of circular saw cuts, and it's covered in paint. It's been outside for the last 4 or 5 years, often as a table for splitting kindling. I was using it last week in the garden to save me bending down when repotting seedlings. It just goes on and on.

All the stuff I've brought from Ikea has been pretty good, quality-wise.

I've got a set of billy bookcases, a metal-framed desk from their 'desks for office' range, two double beds with mattresses, and a 5-seater sofa. It's all lasted fine.

Of course, as a veteran DIYer and woodworker, my furniture has the benefit of being assembled right and treated with respect. And nobody in my household weighs over 150 lbs, which probably helps this stuff last longer.

I know of a kallax shelf and some cheap 3 seater sofa that has been in the wild for under 10y. They survived college living and a few moves. I gave the sofa to a neighbor. I'm not sure if he's still using it or has since gotten rid of it...

Not OP but I have some Kallax book cases (3x4 arrangement) that are 4-5 years old. We moved house 3 years ago and they’re still going strong.

I have a few IKEA metallic tables, for which I do not see any reason why they would not outlast me.

Even the IKEA swivel chair on which I sit all day in front of a computer is about ten years old and it is still good enough. It was however one of their more expensive models.

When my mother was alive, she has also used an IKEA armchair for about a decade and she was very satisfied with it.

Slightly off topic answer, but - I’ve been sleeping on a king sized IKEA mattress for about ten years now and I have absolutely no complaints. No moving parts or assembly required obviously, but nonetheless never had a bad nights sleep on account of this mattress.

We have a modular sofa system that has moved with us two times already and there are no connector or stability issues at all. Same for a large dining table and various bed frames.

Everything that has metal connectors with fasteners on both sides still works well on 2nd or 3rd assembly in my experience.

Don't remember the product names, sorry for that, but this story happened probably 8 if not more years ago:

I was looking for a new work desk, planning to spend no more than 500 PLN - because IKEA is cheap... All desks within that price were wobbly pieces of glue and wood dust; then I found one for I believe 1500 PLN, 3x my intended budget, but imagine that: actual full metal frame! I could sit on it and it didn't even squeak, much less wobble. So I got it...Really love that desk, no problems with it over the years.

So yeah, they have cheap temporary stuff, but usually also have at least a couple of higher-end pieces per category... with accordingly higher prices.