If you have told your friends about investing in crypto, of course that is very good, but you have to explain in detail about the investment about the risk of losing their money if they make a mistake in the investment they make and if they prefer to invest. There is certainly nothing wrong with altcoins, but they must be able to know for sure the type of altcoin they will choose and don't make a mistake in choosing the type of altcoin they will invest in so that they experience losses on the investment they make.
I don't think it's appropriate to use the phrase "have to" in this case. Still, the people to whom we give advice accept it on their own. They always have a choice and may not follow our advice. They take responsibility for decisions made. Our task is to express our opinion on this matter and present compelling arguments. Then it's up to the one who makes the decision.