BTC investment is very safe and you get the benefit at least 5 times within the 3 years but the altcoin investment gives you thousandth times of benefit when time comes. Just you need to invest in safest altcoins like the Litecoin.
I am not very sure about the 5x returns within 3 years. It depends on the market. If the market rises an hour after your investment, it could give some good returns within days and not really in years. However, for long term gains and to become the crypto guy, you got to hodl your coins and stay in the crypto market. The more you stay, the more prestige attached to your portfolio. Altcoin are good for investment for again, no comparison between the two.