If you had paid 100 BTC for a miner when BTC was worth $100
You mined 101 BTC but BTC value dropped to $50
Would you say you have made a ROI? I'd say not.
You mined 101 BTC but BTC value dropped to $50
Would you say you have made a ROI? I'd say not.
So if you didnt buy miner, you would still had only 100 BTC, it is less than 101 BTC in your example
But obviously if we knew future, we would sell the BTC before the price drops
