Most Monegasques are by and large not millionaires, but they are indeed taken care of by the welfare state very very well. However, they barely make up 25% of the residents, so they are overshadowed by the wealthier foreigners who set up residence in Monaco.
Re: the mobile workforce, there's a tax treaty between Monaco and France (which was imposed by the latter after a total blockade of the former in the 1960s) by which French citizens working in Monaco still have to pay income tax in France, even if they are Monaco residents. It's the only case of "global taxation" of French expatriates in the world. There are, therefore, no incentives for them to live in Monaco. People who set up fiscal residence in Monaco to avoid taxes are, therefore, not French.
Re: the mobile workforce, there's a tax treaty between Monaco and France (which was imposed by the latter after a total blockade of the former in the 1960s) by which French citizens working in Monaco still have to pay income tax in France, even if they are Monaco residents. It's the only case of "global taxation" of French expatriates in the world. There are, therefore, no incentives for them to live in Monaco. People who set up fiscal residence in Monaco to avoid taxes are, therefore, not French.