You Can't Take It With You is all about how you can't take it with you—or, in other words, about how wealth doesn't matter and money won't make you happy. Though, it's also true that wealth is pretty important; the fact that Grandpa owns his own house means that Kirby is stymied in his efforts to take over the entire block.
You Can't Take It With You might be read, not as saying that money doesn't matter at all, but as suggesting that you should spend what you've got on those who matter—friends, family, neighbors—rather than hoarding it for a future in which it will be worthless.
Questions About Wealth
Why is it important that the neighbors pay Grandpa's fine, rather than that Mr. Kirby does?
How does pursuing wealth seem to make Mr. Kirby less happy?
Does the film approve of working for money? What kind of work does it approve of?
Chew on This
Mr. Kirby is a bad person because he pursues money.
Mr. Kirby pursues money because he is a bad person.