1) A Bitcoin developer is buying and storing Bitcoin mining rigs in anticipation of their value increasing after the next Bitcoin halving event in 2024.
2) Bitcoin mining profitability depends on electricity costs as well as the value of Bitcoin, and older mining rigs depreciate over time. Countries with very low electricity rates see more Bitcoin mining.
3) Investing in Bitcoin mining machines carries risks similar to investing in gold mining stocks - their values tend to overshoot price swings in Bitcoin but collapse could follow if the Bitcoin market crashes.