They are not, because the blocks are valid 🤷🏼‍♂️

Whatever actually "is" an ordinal? An ordinal is not a thing. An 'ordinal' is just an arbitrary made-up numbering system for 'numbering' Satoshis. And an "inscription" is just a made-up blob of arbitrary data that can be artificially "sold" (but not really) by pretending that ordinals exist. I "give" you the "numbered sat" and we "pretend" that you "own" that blob without necessarily owning any more *actual* Bitcoin. That's all that 'ordinals' are. It's like numbering clouds.