There is no fixed "lifespan" for cryptocurrencies; they are ongoing technological projects as long as their network is operational and in use. However, their value and future depend on factors such as adoption, technological development, regulations, and network stability. Leading projects like Bitcoin and Ethereum are expected to endure for a long time, while less popular or less innovative cryptocurrencies may fade away.

Factors affecting a cryptocurrency's "lifespan":

Technological sustainability: The network's ability to evolve to meet challenges and keep pace with innovations.

Acceptance and adoption: The extent of its use by individuals, institutions, and merchants.

Regulatory environment: Government laws and regulations play a crucial role in its stability.

Competition and innovation: The emergence of new currencies with better technologies can threaten established currencies.

Liquidity and trading volume: High trading volume reduces volatility and increases the currency's reliability.

Examples:

Bitcoin: An established and stable currency, expected to endure thanks to its widespread adoption.

Ethereum: A leader in smart contracts and decentralized platforms, and continues to innovate. Litecoin: A relatively old cryptocurrency with a projected future in 2025. In conclusion: Cryptocurrencies don't die the same way as fiat currencies; they evolve or are forgotten. Strong and innovative projects have a chance of surviving for long periods, while others fail. The longevity of any cryptocurrency depends on its success in adapting and remaining relevant in a rapidly changing technological landscape.