You mentioned the line "btc won't give you 5x return" that verily true from its current position although it already got 4x within a year. Well to generate max profit from your money, it is important to diversification. People always advise to holding Bitcoin but I don't see anything wrong if you sold some portion of Bitcoin and by potential altcoins from top. Cause these can give you 5-10x depends on their potentiality. So yeah,that could be your life changing step but don't buy shitcoins
For this you need to research the market well. Not all altcoins are the same and never sell bitcoins for altcoins. Altcoins are more likely to turn out to be shit coins and will never pay as good a profit as bitcoin. Selling altcoins can get less profit but Bitcoin always gives more profit.