That would mean people aren’t using bitcoin not that spam is the issue. I believe there is a limit for demand of spam. Maybe I’m in a bubble, but I have yet to encounter a bitcoin spam enthusiast....
Its not monetary if it will never be combined. Bitcoin was not designed to hold endless UTXOS forever. There cannot be 2.1 quadrillion UTXOs and we should not try. Combining is necessary for money. Spam inhibits that.