It’s really hard to attract people of old generations like your parents because they will stick to what they already know and are used to. Also not all people knows about crypto already. If you are going to tell them to invest in crypto, you should consider to teach them first or introduce cryptocurrency to them. After that you can persuade them little by little.
What's more, crypto is very volatile, and I'm sure most of the older generation doesn't quite like assets or investments with high fluctuations, because most of them tend to play safer even though the profit will be less.