I was thinking along the same lines, and understand the difference of PoW vs PoS.
Whereas PoW can easily be defined for bitcoin (number of blocks * difficulty nonce@average power consumption of miner hardware), it get's more difficult for PoS. If you could outline a bit more, why this should have "nearly the same" power consumption?
To answer your question:
Monies invested in Proof of Stake Cryptocurrencies definitely come from somewhere.
—
Energy is required to run most businesses.
— Proof of Stake Investors are probably wealthy individuals who use
Energy to run their businesses and make money.
— And These wealthy individuals invest this money in PoS Cryptocurrencies.
* In Summary:
Proof of Stake Cryptocurrencies depend on wealthy investors —> Wealthy Investors depend on energy —> so, PoS indirectly depends on Energy.
It PROBABLY cost more energy to produce something in factories than it cost mining hardware to produce 1 Bitcoin.