I don't understand where the idea comes from that IKEA sofas fall apart after 5 years. All of their sofas come with a 10 year warranty, even the cheapest ones. Here's one at the $850 price point: https://www.ikea.com/us/en/p/uppland-sofa-blekinge-white-s19...
Their more expensive ones come with a 25 year warranty and still only cost $2,500: https://www.ikea.com/us/en/p/stockholm-sofa-seglora-natural-...