Are there? I've been searching for a good alternative for the last year or more and I haven't found one. Everything that anyone lists doesn't scratch the same itch as CS. Anything I see suggested is a different take on the genre. It's always the same list including things like Manor Lords, Foundation, Workers and Resources, Timberborn, the Anno series, the Tropico series, etc.
And don't get me wrong, those are all fantastic games that I love for many different reasons. But they aren't what I would want as an alternative to CS/2 or SimCity.
I genuinely hope there are alternatives, though. I'm just frustrated at running into the same list over and over with suggestions for completely separate styles of games.