The Tenth Amendment, as an article of amendment, need not conform to anything in the foregoing articles and clauses, which were Madison's subject in Federalist 45. The amendment changes the document, and the social compact. That is the significance of the Tenth Amendment: it is completely transformational.
Notwithstanding the post-Lincolnian Imperial State's propaganda minimizing the Tenth, the Amendment has not been repealed, but only violated in gross terms by open warfare.
And, for the last time, all powers are reserved to the States which are not explicitly granted to the federal government under the terms of the Constitution. That is the criterion for discerning whether the People or the State possess a reserved power.
Unilateral secession purports to abandon that system and deny the citizens of their Constitutional rights and protections.
The problem with abstracting an action and making it the subject of a sentence, the object of which is the real agent of the action, is that it is inherently confusing. The citizens, the People, seceded. They walked away from the Constitution, and wrote themselves another. Your pretense that "someone done them wrong" and that somehow, an unspecified Somebody did something wicked to the citizens, is simply absurd here.
The 10th Amendment simply made explicit what was already implicit in the document. Madison could, and did, repeat his understanding of the function of federal and state government in the 1st Congress, which he had made in the Philadelphia Convention, and during the ratification phase.
Not only did the 10th Amendment not provide anything new ideas, it further limited the states' autonomy by removing any reference to "expressly delegated" powers of the federal government, and to state's "sovereignty, freedom, and independence." The Anti-federalists had lost on that point in the Convention, during the ratification debates, and now in the Congress which proposed the Bill of Rights.
You like to quote the secessionist mantra, but it is of no consequence. In nearly 215 years there has never been an authoritative interpretation of the 10th Amendment which suggests that it authorizes or permits the states to leave the Union - or do do anything remotely related to that.
The "all powers" argument is for the intellectually weak.