Middle class people don't contribute much to the economy

Imagine what would happen if all the billionaires and millionaires just vanished overnight, their companies would just change owners and everything would keep going. <br>But what if all middle class was gone? It would be a huge change, and a lot of businesses would go bankrupt. Now imagine all the poor people were gone. Nothing would change except that I guess some companies would stop being able to exploit the poor. <br>Overall that means that (a) the poor aren't making enough money to really spend, (b) the middle class are just paying for basic necessities and maybe some minor luxuries and (c) the rich are running the real economy and keep everything together.<br><br>Edit: thanks for the gold and stuff, I made this post in 5 minutes so forgive me for not giving many examples or anything. Also I'm not saying the poor or middle class do nothing to help other people or advance society, just that as far as the economy goes they don't do much.