Vintage furniture, by its very nature, has a higher quality than furniture. At present, materials are more costly now than they have ever been, so the makers of new furniture have to either charge more for the furniture or use low quality and cheaper materials to maintain their prices within their customers' expectations. Add this to the fact that a lot of the mass market furniture available in the market today is made in China and this complicates matters further.See more on Kernow Furniture here.
There are still manufacturers that are making high-quality furniture out of materials of high grade, but you can expect to pay more for these pieces. For instance, if you peruse the website of any high-end furniture maker, you can find that the average price of an upholstered armchair is about $3000. If you search for vintage pieces similar to the upholstered armchair, you will find that they sell for less than $500. Vintage furniture is of course in vintage condition not in pristine condition like the new furniture.
With this in mind, quality varies from one piece of vintage furniture piece to another. Not all vintage furniture is good. But, as a rule of thumb, even the oldest piece of furniture might be more durable than the average piece of furniture which you find in designer showrooms today. This is because such furniture is made from particleboard instead of the veneer or lumber wood used in modern-day furniture.
There are some things which you should check when examining the quality of a piece of vintage furniture. One is the presence of particleboard. It is not always easy to detect particleboard since, in the better quality furniture made before the 70s, you would find few pieces of furniture made out of solid wood and more made out of veneered particleboard. Read more on Kernow Furniture here.
While the presence of particleboard in any piece of furniture is not necessarily bad, it does give you more details. One key to telling if a piece of furniture has particleboard is its weight. If it is abnormally heavy, it could be made of particleboard as it is heavier than lumber core or plywood.
Another thing to check in vintage furniture like sideboards, buffets, desks, and dressers is the dovetail joinery in their drawers, particularly in the back corners of a drawer. Furniture with dovetail joints has been made well.
For pieces of furniture which have been upholstered, the lift test is the best to use to determine the quality. If you lift it, it should be heavy. Read more at https://en.wikipedia.org/wiki/Furniture.