Failure has several meanings
The network may keep producing blocks while failing an individual who lost a key. Price can collapse while every technical rule works. A country can make access difficult without stopping the global network. And a severe bug can split nodes into incompatible views of history.
Operational availability, ledger integrity, censorship resistance, purchasing power and usability must therefore be separated. Bitcoin can perform strongly on one dimension and poorly on another. The word fail without a defined objective creates more emotion than analysis.
Bugs and attacks are technically possible
In 2018 developers fixed CVE-2018-17144, a flaw in some Bitcoin Core releases that included a critical inflation vulnerability. The disclosure says it was not exploited on mainnet, but it demonstrates that open and heavily reviewed code can still contain a severe defect. Independent review, responsible disclosure and prompt upgrades are security layers, not a guarantee of perfect code.
An attacker with dominant hashrate can censor or reorganise recent valid transactions and try to double-spend the attacker's own funds. This does not allow spending arbitrary coins without signatures or forcing updated full nodes to accept excess issuance. Eclipse and network attacks may isolate particular nodes without controlling the whole network.
Future incentives and cryptography remain open
The block subsidy declines and miner revenue is expected to shift towards fees. Research by Carlsten and co-authors presented a model in which irregular high fees create incentives to undercut blocks. It is a warning under stated assumptions, not proof that Bitcoin must fail; future block-space demand, price, miner behaviour and protocol responses are unknown.
Bitcoin uses elliptic-curve signatures that were not designed to resist quantum attacks. NIST has standardised post-quantum signatures for the wider digital world, but the timing and capabilities of a cryptographically relevant attack are unknown. Migration would require protocol work, software adoption and movement of exposed funds; technical upgradeability does not make coordination effortless.
The largest uncertainty may be social
The network is valuable only while people wish to use, verify, develop and defend it. A better alternative, persistent loss of confidence, regulation or repeated failures in user-facing layers could reduce demand and the resources funding security. A protocol cannot mathematically command society to assign it a price.
Surviving past attacks and disputes is evidence of resilience, not immortality. A prudent user therefore does not stake essential needs on a slogan, maintains backups, checks software, distinguishes self-custody from custodian risk and revisits assumptions. The honest conclusion is neither certain survival nor certain death, but that mechanisms can be named, monitored and addressed.