Shared Security via Bitcoin
There are several other security-sharing protocols; however, Bitcoin has a unique advantage for security sharing that other tokens do not.
Most other tokens can be used in DeFi or for native staking to generate yield, meaning that to use them for security sharing, you would need to offer at least an equivalent APY. In contrast, Bitcoin lacks native yield opportunities, so even a modest yield, such as 1%, could incentivize BTC holders to participate in security sharing.