Why anybody needs the DOJ? Each state has it's own police and their own AGs and their own criminal and civil court system. OpenAI is headquartered in California

Why anybody needs the DOJ? Each state has it's own police and their own AGs and their own criminal and civil court system. OpenAI is headquartered in California. California has never been shy of using their state resources to enact whatever regulations they want. As for NAACP lawsuit, that's very confusing to me. First of all, why NAACP is doing that? Doesn't seem to do anything with defending civil rights. Second of all, they are suing xAI for using some gas turbines without some paperwork. Maybe it's true, maybe not, but that's something I have very little concern about - gas turbines is not the issue here. We know how to safely use gas turbines. Gas turbines are not going to uproot themselves and go wreak mayhem on the neighboring town. When we have a company that develops dangerous tools that can break the internet infrastructure, gas turbines' paperwork is not something that looks as the first priority issue to me.