People seem to have some misconceptions. If we assume the cost of the mining hardware becomes negligible over time, then the cost of mining bitcoin is the cost

People seem to have some misconceptions. If we assume the cost of the mining hardware becomes negligible over time, then the cost of mining bitcoin is the cost of the energy. The amount earned by miners is: mining reward + transaction costs. The mining reward will decrease over time, so in the end it should be the transaction costs. Now, we then get that as t --> big transaction costs = cost of energy because spending more energy than you make on Bitcoin loses money. People should be incentivized to reduce their transaction costs by going off-chain, using a POS chain, or other means.