I don't believe the current fee rates are an attack. It just made me wonder if fees are a possible attack vector on the usability of the network.

I may have chosen DDOS as a poor wording, but to my layman eyes it still seems like a similar concept. Flood the mempool with intentionally bloated and expensive transactions with the ill-intent to disrupt actual users from transacting (unless willing to outbid).

BTCExecutor

bitcoin

Are transaction fees a vulnerable attack vector?

I doubt that this is an attack. If you call it an attack it is definitely no DDOS attack. A DDOS attack floods a resource to disrupt the service it provides. If you flood the mempool with transactions everyone can perfeclty fine use bitcoin and the mempool. Of course you have to outbid the flooder on feerates which could be potentialy expensive. But there is no disruption of a service and therefore no DDOS.