The metallurgist would like to chime in.
Piano/Music wire has been around for a couple of centuries.
In spite of the all the amazing developments in metals, Music Wire is flat out the very strongest piece of metal that you and I can buy. NASA, or others with deep pockets, can get stronger stuff but nothing, absolutely nothing commercially available beats music wire.
The strength comes from how it is made, not from any magic in the chemistry.
That is why it is so much fun to cut.
If you like coil springs & choose to cold form them from music wire, best practice is then to "set" the spring by heating about 350F (wife's oven) for a while.