Yes it is sound money as every secure token thats good to measure a value with. That doesnt mean that bitcoin is a replacement of any other type of money. Usualy its the bad money that is so numerous and so widespread that it literaly wash out the market of other currencies, like fiat does.
Besides that Bitcoin is way to slow as an replacement for money.
Yeah, bitcoin is really good to have, we can save it from our wallet and it will be hard for us to spend all of it, I mean not that hard but it is really good to save bitcoin because of the value of bitcoin is increasing. Bitcoin really sounds money because we earn and save it just like fiat.