Just wondering, why only BTC and ETH? Few altcoin such as BNB and ADA are currently popular and have high market cap.
BNB is not an altcoin/ It's a gambling, and if you like gambling, go to Las Vegas.
ADA and others fall into the same category, so it is better not to invest in a lot of the same category.
Smart contract have lots of application, it's not limited on token. Simply saying "Smart contract" on your class is more accurate.
I mean tokens, but I added the word smart contracts to fit the content of the article.
Buying any altcoin does not mean diversification because they are all in the same category - cryptocurrencies. Why take the risk with a random altcoin which is far more likely to drop to zero than it is to make any real gains, when you can just stick to bitcoin. If bitcoin dies, your altcoin dies too. If your altcoin dies, bitcoin doesn't care.
Not all of them are in the same category, if we ignore the central nature of stablecoins, they do not take the same approach as Bitcoin.
Some coins take a different approach to Bitcoin in times of stability.