If I start mining Monero, it doesn't matter if I use an ASIC machine or a PC. My hashrate is irrelevant, and I will delegate all my power to a mining pool like Nanopool. In doing so we see that POW is just DPOS with extra steps and extra unnecessary layer 0 governance structure.
What are mining rigs if not capital? To take over a PoW network through hashing power requires a monetary investment in computing power. You could just as well leave out the pointless computations altogether.
The separation of security and governance from the stakeholders is a significant one.
On networks where stake and governance are intertwined, attackers can buy stake and attack the network risk-free up to a certain point. However with something like POW mining, the profits are razor thin. Trying to attack the network usually fails, AND it costs a shit ton of money. Even in the event of success they've probably still lost money. On a proof of stake network we've already seen that a hostile takeover requires forking out attacking stake, which is bad policy and seen as unacceptable to a network like BTC.
Again, the ability to turn energy into money while also securing the network isn't "pointless computation".
It's magic.
It's an extremely important tool moving forward.
And it creates unhackable random numbers that no one is even using yet.