> Regulations require a bureaucracy in order to be effective.

That's a very European point of view (though not uniquely European, it's also shared across many other cultures, e.g. in East Asia). The US has done pretty well with private rights of action. In fact, because our culture is so conservative and anti-authoritarian, centralized bureaucracies are rather quickly defanged or grossly underfunded. The most recent example is the Consumer Financial Protection Bureau, and more quietly the FTC. Democrats would have done much better to roll back judicial expansion of the Federal Arbitration Act and devolve "regulation" back to states and private class actions, rather than to create the CFPB and elsewhere double-down on anemic, extremely inconsistent, and often highly partisan agency regulators.

Where private rights of action tend to fail is when they concern inchoate or non-individualized harms, like you often see in environmental protection law. Then what you get is complete paralysis, such as with real estate development; largely because its the process, not the end-state determination of rights, that private actors weaponize. But when they're firmly anchored to property rights, personal injury or loss (including fraud), etc, they seem to do as well as centralized regulation. And in the US, they arguably do better, because of our political dynamics.