It's hard to make 100x gain from Bitcoin or Ethereum and 100x is enough to change someone's life for good, imagine investing a thousand dollars in an altcoin and the altcoins just shoot over the roof doing 100x that's 100k in dollars, this is the dream of every altcoin investors, but also altcoin has the most massive damage, all your money can go near zero.
You can still gain this profit in Bitcoin, but it takes time, like a year or so, by holding it, which is safer, but it is not like altcoins, where if you find a promising coin and invest in it, you can be doubling or more your profit because once it's listed on an exchange, you'll make massive profit on it within a week or a month, but again, the risks are high, which is why people loved it more.