I don't disagree, but Orochimaru's still a cut above in terms of wild effects. The cannibal seal for one, as well as whatever seal apparently identified Hazou as a relative of the Uchiha and whispered in his ear. Even on the more conventional side of things, his demonstration in the Orbularium is very much not how we would approach the creation of a high-yield destructive seal.
It's not that Orochimaru has ideas that we're fundamentally incapable of thinking of, to be clear. It's that we tend to aim for the most reasonable-sounding version of a given idea, because the only real lever we have to reliably make seals easier is minimalism: strip down the extra features, pare it all down to the minimum viable sealtech. Orochimaru, by contrast, seems to have the knack for just figuring out which bells and whistles are most compatible with a given seal idea, and which esoteric seal ideas can be realistically done without even any of that minimalism. I'm not saying that we'll be locked out of figuring out creative effects without watching him, but it'll sure be a heck of a lot easier if we can just watch him venture off to some distant point in concept-space because he happened to see a path there, and then we trace that path itself and figure out all the ways we can branch off of it.