Most of altcoin blockchains can give people cheaper transaction fees than Bitcoin blockchain. Security is good, risk of reverse with Bitcoin blockchain is zero, I can say it's is very small so assume it's zero, but if people only need to move small fund, use altcoin blockchains good alternative solutions when they can not afford to pay expensive fee with Bitcoin blockchain.
Many beginners and financially illiterate people fall into this trap, not understanding what money is. Bitcoin isn't just a digital currency but also a monetary network, akin to Fedwire or CHIPS, electronic systems managed by the Federal Reserve for settling large-value transactions among financial institutions. Bitcoin is an alternative to Fedwire; it has the potential to become a global reserve currency. Bitcoin's Lightning Network can be likened to Visa and Mastercard systems, enabling fast and inexpensive transactions. Anyone can be their own bank, opening LN channels and engaging in large-value settlements.
I think it's important to understand the distinction between Bitcoin and altcoins. In my view, all altcoins are scams. They're typically created by people with questionable moral and ethical principles who reserve a large portion of the supply for themselves in advance. For example, Charlie Lee, the founder of Litecoin, Justin Sun, the founder of Tron, or Ethereum's founder Vitalik Buterin—all have enriched themselves by deceiving people who don't understand what Bitcoin is.