"The judicial Power shall extend to … Cases … [and] to Controversies …"
US Constitution, Article III Sec. 2
We all know roughly what that means, right? No advisory opinions from the federal courts; no decisions about hypothetical cases. I admit that I'm no expert in the doctrine in this area, though I do watch it out of the corner of my eye, and I can't recall reading a more ridiculous standing decision in the last 10 years or so than the one the Court endorsed in the 303 Creative v. Elenis case (holding, on the merits, that the designer of a wedding website has a First Amendment right to deny her creative and expressive services to same-sex couples). If you know of one, I'd love to know what it is.