In 2017, Bitcoin faced an existential crisis. As adoption surged, its 1MB block size limit led to clogged networks, soaring fees, and existential questions: Could Bitcoin scale without sacrificing decentralization? The ensuing "Scaling Wars" pitted developers, miners, and users against one another in a high-stakes debate over technical solutions, governance, and Bitcoin’s soul. This post revisits the conflict, exploring how Bitcoin emerged stronger—and what it means for the future.
a) The Technical Problems They Solved
Blockchain Clog 101
Bitcoin’s 1MB block cap, once a safeguard against spam, became a bottleneck. Transactions piled up, fees spiked, and users waited hours (or days) for confirmations. The core challenge: increasing throughput without hard forks that risked chain splits.
Enter SegWit and BIP-91
SegWit (BIP-141): A soft fork that optimized block space by separating witness data (signatures) from transactions, effectively increasing capacity to ~2MB.
BIP-91: A clever activation mechanism requiring miners to signal support. Once 80% of blocks endorsed it within a 336-block window, SegWit would lock in, avoiding a contentious hard fork.
Why it mattered: SegWit fixed transaction malleability (paving the way for Lightning Network) and boosted capacity, all while maintaining backward compatibility.
