Sometimes it happens that altcoins are more profitable than Bitcoin, nor to deny that. Like investing coins that are in hypes gives us x2, x3, multiple times in general, and that is good.
The chance of you from getting profit x2 or more is the same chance or more to getting loss. Unless you're investing alts that were established already, like those top 20 coins listed on cmc. BNB is more impressive coin to invest either in short term or long term. For eth it should be in long term.
The chance of profiting from altcoins is relatively the same in BTC. The difference is, the former has a bigger chance of flopping due to its uncertainty and longevity. Bitcoin, on the other hand, has proven its dominance on the market over the course of its years. Though its price may be volatile, the amount of security that you get is somehow higher compared to alts.
Though I do agree that if you invest into the top 10-20 altcoins, there may be a chance of doubling your investments. But of course, everything is a double-edged sword- either you win or you lose.