Although in my opinion this is not true regarding 80% of altcoins, I still think there's something valuable in these words. Yes, probably most altcoins will disappear in the next 5-10 years, but those which will remain will surely rise in price 5 times and more. You just have to decide for yourself what you believe. If you believe that all this crypto thing is just a financial bubble then stay away from it and don't invest a dime. But if you think that it's hard to imagine the future of this world without blockchain technologies and without cryptocurrencies, then choose 5-7 coins from the top 20 on coinmarketcap, and invest in them (but not more than you can afford to lose) and most likely you'll be in big profit sooner than it may seem today.