Last time I bought a couch, a new one, it set me back $6,000. It took me the better part of eight months to find it. Solid wood. Proper joinery. Thick padding. Pig skin leather. We kept it for 20 years before giving it to some friends who had it reupholstered where I expect it will last another 20 years.
I used to have some expensive, but ultimately crap, book cases. Book cases are not designed by people who own a lot of books. 36" to 48" spans of fast growth pine will stretch and bow within a year or two. I designed my own book case. I went to a furniture making store. We went back and forth a few times. The biggest sticking point that took four attempts for the furniture maker to understand was where to put the fixed shelf. It does not go in the middle because that wastes space. We made it out of pine. 7' 8" tall, so that when standing it up, it will clear an 8ft ceiling in modern American homes. 22" wide shelves so they cannot flex. Fixed shelf to counteract gravity. Made specifically to carry paperback novels and similarly sized books. "Sand it three times, prime it, sand it, prime it, sand it, paint it, sand it, paint it, no I don't care that a single book case will cost $200." I bought 24 of them. Many hundreds of lineal feet of book cases. We still have them 24 years later and they are as good as new. And the paint job, because it is two layers of prime and two layers of paint, on a mirror surface, looks like you just took the item from the showroom floor.
I have a plywood bookcase I made to store cooking books. The cheapest plywood you can imagine from the big box store. But because of the structural design, 15 years later it still holds up without any bowing or flexing.
Modern furniture is absolute junk. Even the "good stuff."