People mining for the last 5 years made a killing because difficulty was low and price was low. So they got more bitcoins even though price was low. Now price is high ($10k vs. below $800 back then) and difficulty even higher. The whole premise behind mining is to accumulate more bitcoins as bitcoin pricing was just secondary to mining. But now you get less and less bitcoins everyday and that's going to continue. If you spend $2600 to get an S9 + PSU running, it's going to take a full year to make 0.41 BTC (2 weeks ago it was 0.47). If you spend the $2600 and buy the BTC instead of the miner, you'll have about 0.25 BTC now. If you mine with the S9 it's going to take over 7.4 months as of TODAY. Depending on the difficulty increases, it's going to take even longer than the projected 7.4 months as the calculator assumes no difficulty increases.