Literally the bourgeoisie

I am going to be eternally amused by Cities Skylines players/developers realizing that their Perfect Capitalism Simulation... fucking sucks for almost everyone. Including the person ostensibly "in-charge" of the project.

Something about Paradox games just brings out the historical materialism in people.

The in-game answer is that you enact the industry-2.0 policy which reduces the needs of factories to a few educated workers that manage the automation.

The correct answer is crime and living standards that affect the level of education people attain, limiting their options. And migrants. And racism and either racist or classist policing(or both).

Print more money and tell everyone that the inflation is transitory, this will shock the economy to help jumpstart your new poor. Companies will lay off underperforming workers and the restriction of capital will limit new company initiatives so they won't get rehired. Limit the supply of housing everywhere except very high density near your desired factory sites and provide generous subsidies to builders. This will keep your voting body relatively stable so you can get re-elected but create a new serving underclass. Hope this helps.