What Is a Major Bottleneck to Throughput on Public Blockchains like Ethereum?

The major bottleneck to throughput on public blockchains like the pre-Merge Ethereum was the Proof-of-Work (PoW) consensus mechanism, which limited block production speed. Additionally, the execution of all transactions on a single chain (monolithic architecture) and the need for every full node to validate every transaction created severe limitations.

This competition for limited block space leads to high gas fees and slow confirmation times during periods of high demand.