Life expectancy of a good couch

I'm looking into buying couches and was looking at Costco. I went to customer service to ask what kind of choices they usually see returned etc and those kinds of questions. They told me that they have accepted 5yr old couches and how sometimes customers claim that there's an issue but they didn't always see it...anyways I asked them many questions about what they see or patterns of products that are returned etc but they couldn't answer one of my question, they just didn't seem to know what to say. Perhaps y'all know. How long SHOULD a good couch last? We have couches from the early 90s that we purchased secondhand, which are still in great condition. My kids jumped on them when they were younger and are still holding strong. The other set we have in our tv room, which one of the couches is still 'good enough', but seems to have a spring issue... probably from our kids. Anyway we want to replace our TV room couches. The one we like is over $2000. Nowhere near the price we spent for our current one. The costco employees just said if we do have issues, we could return them, but i honestly don't want to get side eyes from people. My kids are no longer in the jumping on couches phase, but I would imagine that couches should still be able to withstand more than 5 yrs. Dang, I'm long winded, I'm sorry for that! but honestly, how long should a good couch last?