Stupid, dishonest, uninformed, and/or politically motivated actors can dispute it or pretend to dispute it (and before you ask which one you are, you're politically motivated). I wouldn't consider any of their attempts reasonable. The language of Section 3 does not give Congress the power to disqualify those who've taken an oath of office and then committed insurrection or given aid and comfort to those who have. It by its express language disqualifies anyone who has done so and gives Congress the ability, with a supermajority, to remove that disqualification.
No other provision of any of the Civil War amendments has been held to require legislation to give them effect. Congress wasn't required to pass any legislation for Section 1 of the 14th Amendment to have legal effect. The framers of those amendments were suspicious of the judicial system that had produced Dredd Scott, so included enforcement clauses in the 13th, 14th, and 15th Amendments expressly authorizing Congress to pass legislation to supplement and enforce the terms of those Amendments, but such legislation wasn't required for those Amendments to have any effect in the first place. This is a new requirement this Court invented because it was politically convenient for them to do so.
The real legal question should have been did Colorado correctly determine that Trump had committed insurrection? If that invited mischief from other states, it would be the Court's duty to slap that shit down. That's the job these people wanted.