> It would not only mean that Congress can create independent agencies, but that all cabinet officers are independent by default. Nobody seriously thinks that’s true, but that’s the implication of the non-redundant reading of the Opinions Clause.

No. "By default"? That's a really weird way to make this sound crazy when it simply isn't. Congress is the branch that creates the departments and creates the legal framework around them in the first place. The president faithfully executes the law. That's not unserious, that's literally the point of the whole system.

A realistic Congress is, generally, not going to pass an act establishing an entire department and somehow neglect to prescribe how the heads are appointed and removed. (!) If it did that for some reason, then yeah, the heads would "by default" be independent, until/unless Congress prescribed otherwise in the future. And... so what? Either that'd be deliberate -- in which case it's equivalent to explicitly prescribing their independence, so it makes no difference unless your real belief is that Congress can't even prescribe this explicitly -- or it would be the result of hundreds of people simultaneously goofing, in which case they can just... fix it by passing another act. Or they deliberately wanted to sow chaos or play games by leaving this unclear, in which case... what else do you expect. In that case it's up to the voters to vote them out, or for courts to rule something if this silly hypothetical ever happens.

All of which is to say: "by default" basically means nothing here. It feels like a pointless argument with an agenda. The idea that the "by default" scenario somehow means some clause was superfluous and deliberately added for funsies is the unserious take here.