In any real-world application of socialism I've seen, it is indeed the government deciding how much one is given. I can't think of any implementation where the government asks the citizen how large of a slice of the pie they'd like.

I'm happy to be proved wrong, and maybe someday there'll be a successful communist state, but until then I look to history.

Right. I suppose I can't fault you to equate all of socialist ideas with what you have seen.

There are socialists who are anti-state, for example. Check out Anarcho Communism, who very much use the "...according to their needs" ethos.

I'm all for blockchain socialism, but I doubt it will be called that ...