That wouldn't happen if you converted bitcoin for ETH or dogecoin at that time, and you would even made more profit than holding bitcoin if you had held them until now. Because as I remember, ETH price in 2015 was only 1$ while doge average price was 0.0001$.
I don't recommend people invest in altcoins because it is significantly riskier than bitcoin, but it is clear that not all altcoins are the same and they will all disappear over time. There are a lot of altcoins that were created 10 years ago and they are still around and growing today.
Usually, the whales first invest in BTC, pump it and at a certain level, take profits and move the money to the altcoins and then again get profits.
Right now, we are seeing the same transition where Bitcoin isn't moving much, but ETH is leading the rally. The bitcoin dominance is decreasing, and I think a big altcoins season is awaiting us. However, I do not say that convert your bitcoin to ETH or altcoins, but if you have extra fiat money, it is time to invest in some altcoins and make quick money. But in the long term, bitcoin is the only and safest investment.
We are currently seeing a significant shift in the cryptocurrency market, with Bitcoin's dominance starting to wane and ETH becoming the leading force in this rally. As mentioned, whales tend to use Bitcoin as an initial investment and then move to altcoins to maximize profits. However, it's important to remember that while altcoins offer the potential for quick profits, Bitcoin remains the safest asset for long-term investment. Indeed, if you have additional fiat funds, this could be a golden opportunity to invest in a growing altcoin. However, if you're focused on stability and security, Bitcoin is a wiser choice. This market movement is a clear example of the highly dynamic nature of the crypto world, which relies heavily on timing and precise calculations.