Yes local materials production on Mars will be important. But I think there will be a period before that is running where we could still send like ten simple rovers and that would be an interesting mission compared to how we have been doing it.

One thing of note, it’s too cold on Mars for rubber (as far as I can tell). The tires are one part of my robot that wouldn’t work. NASA developed some elastic-mode Nitinol tires that would do the trick.