Not many will move from using inscriptions (Taproot input scripts) to OP_RETURN (an output type). But some that are storing arbitrary data that aren't inscriptions (JPEGs etc), but are using fake public keys creating unprovably-unspendable outputs that permanently bloat the UTXO set, will hopefully switch to OP_RETURN.

This is the insane thing to me. The witness discount was put in place to incentivize not creating additional utxos, but has had the complete opposite effect. What's wrong with admitting it was a mistake?

Right, that's why I qualified my statement with "to the extent that"

I hope the spamming is just a fad and all the spammers lose all their money. No one needs jpegs on the blockchain and there are better technologies for that.