See Proof of Stake or Open Representative Voting for alternatives which don't encourage waste

> if it was quick, simple and efficient, it would have insane inflation rates, or the entire space would be run through quickly, entrenching the majority of wealth with the early adopters and making it impossible for new players to enter.

Is this not true of proof of work mining already? The majority of wealth captured by miners appears to be going to those who were early adopters or with significant capital. Newcomers can enter and play at the fringes, but they cannot get seriously involved without large capital investment.

To be honest proof of stake looks no better for this at the monent. But no worse either, and at least the energy consumption is a vastly lower.

Not all cryptocurrency are heavily based on CPU/GCU or I/O!!! As someone already posted, neo and nano currency are not based on "heavy" power usage. We could argue what "heavy power usage" is but you can design cryptocurrency not to assume big amount of electricity.

Imagine that bitcoin is 1st and worst cryptocurrency, but the technology can be improved and it's improving!