Because crypto can be said to be too early for everyone in the world even though in fact in some countries crypto is already very popular, but in some countries it may still be foreign and even completely unknown.
So you have to introduce it little by little to your parents so that they understand.
People are easier to encourage if they know that your already earn money thru cryptocurrency. Here in my country, a lot of people know about cryptocurrency because of the game Axie Infinity even the middle age or old people played the game to earn money. I already encourage my sisters to invest in cryptocurrency after they know that I get profit to it. Bear market right now is a good time to buy crypto.