It comes at a different cost: you have to have a constantly updated proof to spend the coins. You can’t go offline and spend coins you know you have SPV style without having someone who has validated the chain provide you with an updated proof. And running an ‘indexer’ node that monitors proofs for all coins is very costly compared to running a node today. That model also increases the bandwidth needed for relaying transactions and blocks considerably. I think but am not sure that you can’t avoid the bandwidth increase by just having a today-style utxo set, because you’d need to provide proofs to non-local-utxo peers.
There is a reasonable argument that the asymptotic behavior means it will eventually be needed, but I think it’s harder to argue that it’s a good tradeoff now. So I think that makes alternatives with other tradeoffs interesting to discuss.