Remember that in the near term the block reward is fixed in BTC and variable in electricity costs. The more expensive BTC, the more power is wasted mining. The BTC has to be sold off as its mined and paid to electric companies. To sustain this selling, more new money has to come in as a function of price to retain stability.

At current price and block reward, Tesla's investment of $1.5B pays only 6 weeks of electric bills.