If miners are paid when they solve a block, how can a miner who is not in a pool make less than the block reward?

Question

I have heard of miners making much less than the block reward and I had assumed they were being paid also for processing transactions which would be potentially many small amounts.

However, if these transactions are associated with the block to be solved, then it seems they would make the block reward PLUS the transaction fees -- a miner could never make only transaction fees.

Or are the miners who make a few dollars a day doing so via a mining pool?

Note that I do understand a miner is likely to make zero because mining is very competitive so what I might have expected a miner to have occasional big wins of 6.25 BTC (plus transaction fees) or exactly nothing.

But I think of the example of the guy in Guatemala who burns used cooking oil in a generator and supposedly makes 200 month -- does this apparently steady return of 200/month imply he is part of a mining pool?

Answer 1

A solo miner (a miner who is not in a pool), can only either win or lose a block. When they win, they get the block subsidy (6.25 BTC currently) plus the transaction fees. When they lose, they get nothing. There is no in between. In particular, there is no such thing as processing individual transactions in the network; miners' only job is producing blocks. Without block, no income.

Almost all miners work in pools however, where the rewards (of both subsidy and fees) are split between all workers in the pool.