[johng]

> The bigger open question is whether the long-term fee market will be sufficient to sustain miner incentives without block subsidies.

^^^ This. Fees are already included in block rewards and (compared to the block rewards) are pretty paltry. Unless the value of Bitcoin goes way up, I don't see a resilient network sticking around with enough hashing power to keep out a malicious actor / bad state actor.

Edit: These charts should give you an idea of how much fees represent in current blocks.

https://charts.bitbo.io/fees-percent-of-reward/

https://charts.bitbo.io/fees-per-day/