Broad diversification is key to success in investing.
Saving money in 2 coins or stocks can wipe half of your capital if one of the two goes south.
Put your dough in 5-10 coins, if one of them collapses you only lose 10-20% of your capital and can quick recover your losses. Read what professional investors do, they recommend investments spread over 10-20 ventures. Above 20 is difficult to keep track of. But 5 is a bare minimum, everyone can keep track of 5 coins and be insured against large unexpected hits.
In crypto broad diversification is picking coins with original code that are not Bitcoin clones. You diversify the software and the devs, programming languages.
To add to that, I would say that the majority of your portfolio should be in bitcoin. Alts can be used to give you that extra profit, but you shouldn't bet your house on alts.
Buying an alt is like buying bitcoin leveraged. It's much higher risk than buying bitcoin, you can make much bigger gains or lose everything. If you stick to bitcoin even if it goes down you still get money back if you decide to sell. With alts you can get much less back, or nothing if your alt dies.