Proof of Work was the 1st used consensus model, initiated by hashcash in 1997, and widely used with bitcoin and its forks. It allowed running a network without having to trust the maintainers. But there's still some problems...
Energy usage
PoW uses many energy because of its main principle that needs to run energy-eating computers. Researchers calculated a bitcoin transaction used 77kWh.
It's also the reason for ETH2.0 to switch to Proof of Stake.
Low scalability
There's a less-known problem. Because of we doesn't know when will a valid hash be found, we cannot predict when will a new block arrive. And if someone mines another block without knowing the real last one, it would lead in an unexpected fork.
And the solutions are :
- increasing avg block time, for giving blocks more time for being transmitted
- reducing block size, so makes blocks easier to broadcast
But in both cases, we reduce scalability.
So, will PoW continue existing ?
Proof of Work has problems, but PoS also has some. But I don't think so much blockchains will migrate to PoS because of it's very hard, and because of there's also problems with Proof of Stake model (I will write an article about)
