The argument in support of UTXO aggregation that suggests it can mitigate spam on the Bitcoin network is a compelling one. Covenants, which are a type of script used to share UTXOs between users without requiring custodial services, would make monetary transactions more cost-effective and thus better equipped to compete against spam. However, an important detail that needs to be acknowledged is that covenants reduce the amount of fees miners receive, which goes against their economic incentives. Lightning, a type of scaling solution, also falls into this category as it reduces miner fee income.
This argument presents an apparent contradiction with the idea that spam filters are not economically feasible because they too go against miner incentives. This raises an interesting question: why would miners accept Covenants or Lightning but refuse to implement spam filters?
The answer lies in the fact that spam filters, like CTV and Lightning, ultimately improve network efficiency, which will have a positive economic impact on miners as it increases the overall value of the Bitcoin network. Mining is not just about earning fees; it also involves securing the blockchain through mining work. By improving network efficiency, these solutions make it more profitable for miners to secure the chain and receive block rewards while reducing their dependence on transaction fees. As a result, they become economically beneficial for all parties involved - users, merchants, miners, and Bitcoin as a whole.