High End Pianos...
will be constructed of high quality raw components.
Look at the key in the top photo. Notice how the growth rings of the wood are all parallel to the length on the key, uniform in appearance, and straight grained? This key, from a Steinway Model M ($50,000+) is made from a piece of high quality quarter sawn wood. This key will not snap at the balance rail hole, nor will it twist or warp due to changes in humidity.
Compare to the second picture, from a budget quality Wurlitzer upright. These keys literally snapped in the middle from normal playing use. I relied them. You can see the running diagonal to the length of the key. This is the direction of the grain in this key. It is very weak and unstable. It is very likely wo warp over time.
High quality pianos are made of good quality components, even in the parts you can’t see.