Not at all. Ark and Lightning as examples, both are completely valid and provably spendable bitcoin transactions that simply are exchanged and updated without ever needing to publish on the base layer. It is neither an IOU, nor a different asset. It’s just a security design where you can move bitcoin outside of the base layer and know that the rightful owner is the only one who can spend it without anyone else having the capacity to revoke.

There are cases of course where someone can just make a new token or an explicit IOU, like ecash does. But it’s still denominated in BTC.