This is unfortunate but you are not responsible of everyone you meet or know

Their decisions are what led them to this you could’ve prevented this, yes but even if you taught them properly how sure are you that they won’t fall victim to any other scams out there? or make bad decisions regarding investment? Cryptocurrency is far from a secret and there’s lost of articles/youtube videos/podcasts that explain crypto, trading, and investing for beginners

Anyone could’ve done their research I do get the guilt this comes with though but there’s really nothing you can do anymore