Why do we not use Istanbul Byzantine Fault Tolerance IBFT in Public Blockchains

Question

Why is IBFT not used as a consensus protocol in public blockchains? After all, it is Byzantine-Fault-Tolerant and prevents forks, which is more than for example Proof-of-Work in Bitcoin does?

Answer 1

The use of the IBFT consensus involves the allocation of a special pool of validators, no more than a few dozen, which, by collecting explicit confirmations from each other, determine the validity of the block and the possibility of its inclusion in the chain. For the public Ethereum, this, firstly, violates the very concept of equality of nodes in the network, and secondly, when trying to expand the pool of validators to a comparable number of nodes participating in the public Ethereum, it will inevitably lead to the collapse of the consensus process.

Hence, in the public Ethereum, the PoW is used, which does not imply the presence of "special" nodes and any explicit confirmations - the consensus is based on the fact that following the general rules: finding a "lucky" hash and adding a new block to the longest fork, the node has the highest probability of receiving block creation rewards.