In "The World is too Much with Us," the fact that the world is "too much with us" implies that it has gotten too big for us to handle; cities have gotten bigger, more shops have opened, and it is now possible for us to spend all of our time "getting and spending." Even though it might be nice to have indoor plumbing and a wide variety of shops to visit on the weekend, such advancements come with a heavy price, at least according to the speaker of the poem.
The speaker critiques a culture of "getting and spending," but he is also a part of that culture and thus obsessed with "getting and spending."
The poem suggests that only primitive, pre-modern cultures can experience nature as something truly marvelous.