Can Increasing Transaction Fees Deter a 51% Attack?

Increasing transaction fees alone is not a direct deterrent to a 51% attack. The attacker's goal is to execute a double-spend to steal funds, not to profit from mining fees.

While higher fees make mining more profitable, potentially attracting more honest miners, this effect is often too slow to counter a sudden, massive influx of rented hashrate. The attacker's cost is the hashrate rental fee, which is largely independent of the transaction fees.