"Regulatory failure" means that the people in charge of making sure everything is safe and fair didn't do their job right. It's like if your teacher didn't notice that someone was cheating on a test, or if the referee didn't see someone break a rule in a game.
When we talk about regulatory failure, we're usually talking about things like laws and rules that are supposed to keep us safe and make sure everyone plays fair. This can include things like safety regulations for cars or rules that companies have to follow to make sure they're not hurting the environment.
But sometimes, the people in charge of enforcing those rules don't do a good job. Maybe they don't have enough resources, or maybe they're not paying close enough attention. This can lead to problems like unsafe products, unfair business practices, or other things that can harm people.
So when we say there's been a regulatory failure, we mean that the people who are supposed to be keeping everything in check didn't do their job as well as they should have. It's important to try to fix these failures so that everyone can be safe and treated fairly.