ip based voting on blockchain would give control to the internet providers, plus allow every "miner" to be tracked through their IPs. Plus creating IP addresses is not a hard task the way PoW computation effort is.



For validating transactions you either need something self-contained within the system so it is therefore controlled by the system itself - this is how Proof of Stake works, or you need something that requires an external scarce resource in its raw form without any need to trust that resource.


Computational work is an external scarce resource. There is also some crypto that uses hard disk space which is another external scarce resource though I guess that sort of mining quickly destroys hard drives so that idea failed. IPs are not a scarce resource so that doesn't work. Identity is a scarce resource but would require trust to verify the identity and the whole point of Bitcoin is that it is trustless. People have at times suggested all that mining computation work should go TOWARD something to make it "useful" but that requires a trusted body to decide what the work goes toward so that doesn't work. The reason nobody has come up with something better than PoW is because it is hard to figure out something that would be better and still accomplish the same thing. You need a raw scarce external resource that itself requires no verification/trust and can't be spoofed, and of course it needs to be able to be directly input in a digital fashion.