True, but judges should be used to ruling on cases involving technical details they don't fully understand. They could refuse to weigh the opinions of outside experts, but I don't think they would.
Besides, this works in other countries, in the Czech Republic for instance, I'm pretty sure I've seen lawsuits against regulatory agencies here.
Chevron doesn't prevent lawsuits. All it does is require the judge overseeing the case to give deference to the regulatory agency when there is ambiguity in the law.
Really simple example:
Congress passes a law that requires the FAA to regulate the safety of commercial aviation, but doesn't explicitly say "all panels must be bolted to the fuselage".
FAA decides any removable panel must be positively attached to the fuselage using castle nuts and pins or an equivalent design.
Boeing thinks that rule is wrong (overbearing, overreach, poorly conceived, whatever).
Under Chevron, the judge hears both sides, and defers to the FAA on the issue of safety. The law wasn't explicit about design of door panel fasteners, but was clear the FAA should regulate the industry.
Without Chevron, there is no deference to the experts at the FAA. The judge is free to impose their own worldview on the case.
Note that with Chevron in place, the judge can still determine the FAA overreached its authority (like if they decided to regulate car transport on the way to the airport). The judge just can't ignore the presumed expertise of the executive branch in applying details to Congressionally mandated regulation.
Without Chevron, we trade executive expertise for the whims of an unelected judge. While bureaucrats are unelected, they are still beholden to Congress for both funding and legislation allowing their existence in the first place. The President can't simply conjure regulators out of thin air.
Besides, this works in other countries, in the Czech Republic for instance, I'm pretty sure I've seen lawsuits against regulatory agencies here.