It's precisely that - in this day and age, a sane miner would never burn fees or rewards - they would take the maximum amount possible, given the equipment and electricity costs. So this method of burning cannot be counted on to be utilized.
There are a few cases of miners who either accidentally or deliberately burned coins. The reward of
block 501726 was failed to be claimed. In
block 124724, the miner destroyed 0.01000001 BTC, 0.01 in fees and 1 sat in block subsidy. The person who solved
block 526591 chose to reward himself with half the block subsidy. Genesis block does also burn coins.