That's not entirely true. Back in the 1970s when we tightened up regulation the companies operating nuclear power plants in the US were selling power onto the grid on a cost plus basis. That is, they'd be paid for their expenses plus a reasonable percentage on top of that. And there were regulators looking at their expenses to make sure they were reasonable.
But when they, together with environmental activists, were able to get laws passed that drastically increased the cost of running a nuclear plant the regulators couldn't say no. So their costs increased, but then their profits increased as well through the magic of cost-plus contracts.
That sounds like a classic example of regulatory capture, with incumbent nuclear power plant operators managing to serve their own interests and raise a regulatory moat against anyone coming after them to build more nuclear power plants.
But when they, together with environmental activists, were able to get laws passed that drastically increased the cost of running a nuclear plant the regulators couldn't say no. So their costs increased, but then their profits increased as well through the magic of cost-plus contracts.