I read this differently (and am a former lawyer who worked on administrative law). This is about the "major questions doctrine", which involves a subset of administrative actions. It's not about whether administrative agencies can do anything whatsoever.
> Under this body of law, known as the major questions doctrine, given both separation of powers principles and a practical understanding of legislative intent, the agency must point to “clear congressional authorization” for the authority it claims.
The reasoning for this is that:
> We presume that “Congress intends to make major policy decisions itself, not leave those decisions to agencies
> Under this body of law, known as the major questions doctrine, given both separation of powers principles and a practical understanding of legislative intent, the agency must point to “clear congressional authorization” for the authority it claims.
The reasoning for this is that:
> We presume that “Congress intends to make major policy decisions itself, not leave those decisions to agencies