Also I don't suggest go other alt-coins. They will be all dead in sometime other than btc.
Yes and no It is investment, but Bitcoin is first and in any moment can come Bitcoin 2.0 with better technology and with experience of Bitcoin 1.0 better prepered to conquer markets and break through the mainstream.. and then everyone will foget about Bitcoin and you can forget about your investment .. It is risky business.. and very risky investment..
But what if you are wrong, and bitcoin 1.0 will not die, but will become like retro car? In this case, invested funds will be significantly multiplied...
We cannot really know the future 100%. But in history, all first version will be renewed. And i dont know about BTC. I also not really believes BTC will just 21 millions in total.
At least, keep your mind open.