As long as the amendments were processed and duly ratified per constitutional requirements, then they are valid amendments and per the Supremacy Clause (US Const., Art. VI, Cl. 2) they are part of the Supreme Law of the Land.
I don’t see a problem with Congress being tasked to enforce these amendments. It’s asking Congress to enforce constitutional law.
“As long as the amendments were processed and duly ratified per constitutional requirements . . .”
That is the problem with amendments 13, 14, and 15.
The consent of the southern states to these amendments was obtained though the coercion of federal bayonets.
Consent obtained through coercion is not consent.