Hard Guarantees #11: The Centralization of Bitcoin Client Development

Bitcoin is considered to be the most decentralized payment network of all time. The protocol and the transactions on it operate on a peer-to-peer network that makes the system robust to any one party having undue influence over the network. But its team of developers is arguably the most centralized aspect of the Bitcoin network.

Bitcoin Core has been the most used Bitcoin client by a wide margin for most of Bitcoin's history. For over a decade, Bitcoin Core has been used by over 80% of nodes on the network. It's a near monopoly that has allowed the technical development team to have a big influence on "the people's currency".

Historical data tells us that while alternative implementations like the Bitcoin Knots and Bitcoin Unlimited clients have existed, they have not gained significant usage. Even during the most volatile periods in Bitcoin's development, including the block size wars and SegWit implementation that ultimately led to the Bitcoin Cash hard fork, Bitcoin Core was able to hold onto its super majority.

This dominance matters because it centralizes Bitcoin's development roadmap in the hands of a relatively small group of maintainers. Unlike traditional software projects with a clear governance system, Bitcoin Core operates without publishing a formal technical roadmap. Instead, changes flow through Bitcoin Improvement Proposals and the feature merge process. These are systems that appear decentralized on paper but are ultimately controlled by those who maintain the dominant client.

The SegWit controversy exemplifies this dynamic. What should have been a technical debate among equals became a high-stakes battle precisely because Bitcoin Core's implementation would effectively determine the network's future. When one client controls the vast majority of nodes, its technical decisions become the network's technical decisions, regardless of community sentiment.

Recently, Bitcoin Knots has gained traction and seen an increase in its usage to above 10% of all network nodes. This increase occurred in part due to controversies around Bitcoin Ordinals. After years of near-total dominance, one wonders whether a truly decentralized network can emerge from such centralized development. For a protocol built on the promise of removing centralized control, Bitcoin's client distribution reveals an uncomfortable truth about where power actually lies in the ecosystem.

Has Bitcoin's technical architecture become permanently shaped by the preferences of a single development team?