As a matter of fact, it's very unsafe to depend on a single coin. In otherwords, invest into more than one token by spreading your investment into potential coins but be careful not to invest into pump and dump coins. Above all, make sure to maintain risk management in which ever crypto asset you are investing in.
What if all the altcoins you wisely buy to diversify your portfolio go down just like Luna, FTX, and other coins do?
I think instead of diversifying your portfolio with altcoins, you should focus on adding more Bitcoin to your portfolio since I am sure you believe that the crypto market is controlled by the BTC price.
Bitcoin is the safest investment one can make with less risk if borrowed money is not used.