Why is this even a question?
Because a tremendous number of laws that people obey and, especially, pay money for, simply do not apply to them. But the government is not required to tell you that, AND they can "presume" these laws apply to you and then just enforce them, unless you can show they don't apply to you. And then in order to show them that they on't apply - if you even know that - they make you jumpt through all sorts of hoops to shown them in a way where they are required to "hear" you.
It's major, major bullshit.
So what this particular case is about is whether cops can be denied a very powerful part of their "presumption" against you - mainly, whether they can presume a law applies even if they get the law wrong. You might think that's crazy that they can presume a wrongful understanding of the law, and you're right. But it's done every day, and one of the things Courts do if you point out the damn presumption was over an incorrect understanding of the law is shrug, and say, "irrelevent - the cop has the right to presume, and is not presumed to be a lawyer themselves." Which, o course, means that cops can and do make up literally anything, call it their understanding of the law, and arrest you or seize things from you or bea the crap out of you or whatever.
So this case is a really big deal, and it's reached the Supreme Court because no lower court wants to take away these extreme police powers. Ultimately what is at issue is whether the police even have to follow the law at all, or if they literally are the law themselves. Because if they can enforce based on presuming things are the law that aren't the law, that's just another way of saying there is no law.