Genuinely curious as to why people think this. This is the standard talking point you see about this issue, and it's just not true. Getting rid of Chevron doesn't mean that judges need to become experts in all minutia of a particular field. It means the executive can't liberally interpret statute to their heart's desire. Maybe you mean that you expect more cases to come to the courts if Chevron is dropped, but cases on complex technical matters already come to the courts all the time in all fields. Are you concerned that the volume of cases goes up or something?
Besides, this works in other countries, in the Czech Republic for instance, I'm pretty sure I've seen lawsuits against regulatory agencies here.
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.
People are not interchangeable: if you take a financial regulatory expert from SEC and move them to FDA and ask them to regulate drug adjuvants, you're not going to get great results. Dropping Chevron would put judges in the position of being experts in all the fields where Congress requires regulation.