Blockchain with a built in wallet

Perhaps someone has already created this and I just haven't heard about it. What if a cryptocurrency contained a wallet or wallets for all the OS's built into the blockchain? I realize there would be technical and security issues to overcome, but if those problems could be overcome the currency would be immediately available to anyone downloading the blockchain. The wallet would have to be written in either a universal language or there would have to be a version for each major OS. I would like comments positive or negative, even to the point as why I am stupid to even contemplate such a thing.

Image from Pixbay