ERC-20 tokens have played a pivotal role in the growth of the Ethereum network by enabling smart contract functionality and decentralized finance (DeFi) applications. They facilitate fundraising through Initial Coin Offerings (ICOs) and token sales, allowing projects to launch without building an independent blockchain. The ERC-20 standard ensures seamless integration with Ethereum wallets and decentralized exchanges (DEXs), promoting liquidity and accessibility. Many leading cryptocurrencies, including USDT, LINK, and UNI, operate as ERC-20 tokens, demonstrating their widespread adoption.