I saw something on a friend of mine iPhone I was amazed, this guy has 3 pieces of bitcoin but he didn't look it when you look at him with mere eyes, I ask him how he has come this far, he told long ego he was seriously investing on all kinds of coins with little amount of bitcoin but then most of those coins help him to realized enough amount to buy more bitcoin because that was his primary target. He normally buys those zero value coins when they appreciates it will be enough money, and that's how he convert and swag all to bitcoin and today, he has 3 piece. Is good to be diversified in your investment, somedays something good will come out of one you don't expect.
Know that every investment does not guarantee success and profitability, that’s why if you have the sufficient funds for capital, learn to diversify your investments so that if one investment fails, other investments will still have chances to succeed. However, on part of OP’s friend, he uses altcoins just to achieve his goal for bitcoin. Maybe that was only applicable when altcoins are still profitable but seeing how the altcoins these days gradually lose their value, I don’t think investing in altcoins aside from bitcoin will still be a wise move.