Why doesn't USA raise welfare benefits like in France?

Because to many Americans would take advantage and sit around and collect the money and never want to work. And eventually you would run out of taxpayers to fund it. Working a job that you may not be thrilled about, is work experience and helps build a good work ethic. If you believe you should have a better job, work at getting one while you support yourself instead of living off handouts. (well not you per say, but just speaking on the people who want to collect welfare).