Ends up the USSC will have to decide.
I will argue that the inconsistency in the Supreme Court’s rulings are creating an environment where some independent agencies will receive special consideration based on their function. This sets up an environment where Congress loses out on the collaborative benefits and safeguards of independent agencies in favor of the courts further empowering the Executive.
That said, there isn’t a fourth branch of government and the strict boundaries of branches is a rather… elementary understanding how our government works.
If an independent agency is “unconstitutional” and a fourth branch, how would you define our Armed Forces in practice?
The Supreme Court has power because the express grant of power in Article III; the idea that they could somehow fulfill their role in adjudicating cases and controversies arising under the Constitution and laws of the United States without both deciding what those writings mean and deciding whether something purporting to be a law of the United States was, in fact, an act authorized by the Constitution when that is precisely the source of the controversy before them is patently absurd.
The argument is all of this violates the constitution. There has not yet been a clear principle articulated by the court for treating them differently.
The idea of a unitary executive is obviously being relitigated but there's no question that independent executive agencies have existed for a century.