I'm not sure how useful this is. The furniture I have had usually wears out fairly evenly so by the time something actually fails the whole thing is in a pretty bad state. Having it disassembleable might actually make it worse because instead of strong welds you have screws which can wobble around a bit and make the item less stiff.
There are other items where this kind of thing makes a lot of sense though. My 3D printer is extremely easy to pull apart and replace parts for. I have a full manual for how every single bit goes together and the parts are usually generic things I can buy off ebay for a few $.
The Pursa i3 MK3. The whole thing is open source including all the part designs, hardware and firmware. The creator also designs guides to upgrade your old printer to work better when new designs come out so instead of having to buy a new device every 2 years you just read the manual on making your old device work like the new one.
There are other items where this kind of thing makes a lot of sense though. My 3D printer is extremely easy to pull apart and replace parts for. I have a full manual for how every single bit goes together and the parts are usually generic things I can buy off ebay for a few $.