What do you tell people that are too scared to move out of cash?

I read this today: "$1 you left in cash since 2020 is now worth ~78 cents in real terms. $1 invested in $VOO grew to ~$2.55 today." I have friends with hundreds of thousands in money markets because they have foreseen a crash coming for years. How do you convince friends or loved ones that sitting 100% cash or even 50% cash is a disaster. I'm not trying to get anyone to invest their life savings in $VOO, by all means keep a $100k emergency fund in SGOV or whatever makes you happy. But you can't