Because PoW is easier to implement correctly than PoS. PoW can be as simple as checking a hash (in addition to the basic block rules). PoS has a lot more rule

Because PoW is easier to implement correctly than PoS. PoW can be as simple as checking a hash (in addition to the basic block rules). PoS has a lot more rules, for example Eth has a lot of PoS rules and includes features like slashing which improve economic securities. https://docs.ethhub.io/ethereum-roadmap/ethereum-2.0/proof-of-stake/ https://docs.ethhub.io/ethereum-roadmap/ethereum-2.0/proof-o... When rules aren't by implemented correctly it causes situations like Bitcoin's 2013 fork https://bitcoin.org/en/alert/2013-03-11-chain-fork https://bitcoin.org/en/alert/2013-03-11-chain-fork