I think the point is that because there are no limits initially, it makes it extremely easy for the President to murder half the government who disagree with him as an official act. As long as he uses marines instead of his own 9mm hand pistol on the street it would be an official act because the SCOTUS decision assumes everything he does as a precursor is fine. It provides cover for him to act in that manner, and by then there is no one to impeach and convict and then hold him criminally liable. If you have read Project 2025, then you know their first act will be to fire everyone in the executive branch and military and install only loyalists. I think people are seriously underestimating what Trump and his followers are up to.