Piano is just 300 years old? There's more.

There is a fairly recent recording called “Fantasie” by Alexander Melnikov where he plays a number of different keyboard instruments—harpsichord, tangent piano, fortepiano, and modern pianos.  It is a very worthwhile recording to seek out.

The pianos of Stuart & Sons represent a fairly recent technological advancement in piano design and modern exotic materials are now appearing in pianos.  I am sure the merits of these "improvements" can be debated, but tiny changes have been happening.  It would be particularly nice if piano actions can be made more durable, but, I suppose piano makers have no interest in innovations that will decrease demand for new pianos.