If you want a political analogy, politically, there is no "right or wrong". SCOTUS is not motivated by adherence to precedent, they clearly have an ideological agenda.

They are not, for example, legalizing marijuana, on the grounds that the FDA should not have the authority to schedule drugs. They chose to go after environmental regulations because they ideologically prefer capitalist interests over environmental ones. It is brazenly political, as was their overturning of Roe vs Wade.

But the FDA DOES have the congressional mandate by law to schedule drugs even details regarding what those schedules are.

The difference here is the EPA does not have the mandated far the reaching authority they are enacting which would fundamentally change the entire economy.