But Congress did it anyway, and the SCOTUS has over the years upheld it. There was a landmark court case involving Chevron (the oil company). SCOTUS ruled there saying that the executive branch agencies responsible for rulemaking are experts in their fields, and we should mostly defer to them when their position seems reasonable, and when Congress hasn't passed a law that contradicts what they want to do.
Marbury is a much older case, that made precedent the idea that courts have the ability to strike down laws that they believe violate the constitution.
The current conservative-leaning SCOTUS is skeptical of what conservatives call the "administrative state" (basically: rulemaking done by the executive branch). They seem to not be a big fan of "Chevron deference", and are fully willing to exercise their Marbury-affirmed power to strike down executive actions that they don't believe are constitutional, or don't believe directly stem from laws Congress has passed.