Yes but this is once again where the free-markets and economics come in: if the mass-produced ones match the custom-made ones in price, consumers will start switching to custom-made sofas. The mass-production suppliers will either have to 1) lower the price of their sofas or 2) increase the quality of production to match the quality of the custom-made ones. Both 1 and 2 are great for consumers and this is why competition is so great :). Notice that all of this is driven by the choices the CONSUMER (me and you) make.
This is a very theoretical argument but I don't think it happens that way in reality, because of all the ways that real human beings are not economically perfect agents. Particularly the information asymmetries - it's much harder to gauge the reputation of a small business vs. a big one.
That’s not quite true, because many people don’t have good custom sofa makers near them. Moreover, because they are small businesses, they don’t have the same capacity for marketing as big brands; most of their business is word of mouth.
Also, custom sofas take time to build - not much, but 2-4 weeks or so.
So there are a lot of reasons big brands are convenient. But you pay for that convenience in quality.
Not sure about sofas but when I bought a bed and some bookcases and nightstands last year all from national retailers, the lead time was 4-12 weeks depending on the product. Getting a custom sofa in 2-4 weeks would beat the competition in many cases. Again, the market constraint lies in knowing about the small vendor in the first place and having a way to purchase it conveniently.
