Another way an entity could destroy Bitcoin could be to broadcast a sufficient number of transactions to bid up the cost of getting a transaction confirmed to be uneconomical. The entity could first broadcast 1 MB worth of transactions every 10 minutes with fees averaging 70 sat/byte, then increase this average to 80 sat/byte, and so on.

This attack could have little to no cost to an attacker with a small minority of the network hashpower (or even be net profitable).