I think this is a good analogy. To complement it a bit. There's the problem of bootstrapping. Once all that new city infrastructure and beautiful planning is c

I think this is a good analogy. To complement it a bit. There's the problem of bootstrapping. Once all that new city infrastructure and beautiful planning is complete, who wants to move into that new city that has no markets, stores, bars, restaurants, etc? Desktop is full of old cruft because people use old crufty software today. They must be able to continue to use old crufty software because they need to until a better alternative exists, but they use multiple old crufty software and better alternatives come slowly. Desktop builds the new city adjacent to the old one and makes the grass greener there, but it takes quite a while for the old city to get empty.