You seem to be confusing two different kinds of expertise: substantive expertise and legal expertise. While I agree the courts should respect agencies' substantive expertise, there is zero reason to respect the agencies' legal expertise. Congress and the courts know more about the law than the agencies' experts. Moreover, agencies' interpretations of the law seem to change, depending on who the president is, even though the law itself has not changed. It seems to me they often try to pass off their political preferences as "expertise".
My concern about the Chevron decision is that Congress people aren’t experts in their field as you probably were.
The fact that Gorsuch confused an air pollutant with laughing gas 5 times in his opinion tells me that regulations should be left to the bureaucrats.
You seem to be confusing two different kinds of expertise: substantive expertise and legal expertise. While I agree the courts should respect agencies' substantive expertise, there is zero reason to respect the agencies' legal expertise. Congress and the courts know more about the law than the agencies' experts. Moreover, agencies' interpretations of the law seem to change, depending on who the president is, even though the law itself has not changed. It seems to me they often try to pass off their political preferences as "expertise".