you don't change the design so often...my parents have the same furniture for more than 35 years now. It's an house, not a website

My parents-in-law changed their furniture 10 years ago, previous change was when they moved into the house, which was 30 earlier. And they now talk about changing it again, modern times force people to change clothes, furniture sooner than it was few decades ago.

I would- but that being said, I also just built a 2'x4' desk out of A piece of pre-cut grade A plywood and used some 2x4's that I cut for legs- and side supports- at a local makerspace. Total cost was about $45, not including the membership, and it's my desk that I can do whaveter I want with. I absolutely would spend the extra money on something that lasts 10 times longer, because that generally means that I won't have to replace it, or can resell it when I do.

That being said, I'm not super into fast fashion / 'influencer culture', either, so maybe I'm in the minority here?

Do we really need to exchange the furniture to match current trends? IKEA basically invented fast fashion for furniture, but we don't have to operate that way. Not to mention that is highly unsustainable.