You pay $1000 to a monopolist instead of $100 to a small business and then having the other $900 to spend on whatever you want, like patronizing 9 other small businesses and actually getting something more for your money. The $900 in monopoly rent goes to Wall St instead of Main St and is used to e.g. bid up housing costs so people can't afford to buy a house.
The incumbents lobby for restrictive zoning or professional licensing gatekeeping to keep those rents high, which means fewer jobs doing construction.
It doesn't help you for huge corporations to get more of your money.