Whether to buy more Ethereum (ETH) depends on your personal investment strategy and market analysis. Ethereum (ETH) is a long-standing leading blockchain platform powering centralized applications, finance, protocols and a vast array of non-fungible tokens. So I think buying more Ethereum (ETH) is definitely a good investment decision.
Even though it's the second-best cryptocurrency in the market after Bitcoin, one should do ample research before one makes their own decisions. I don't think that one can get a better altcoin than ETH if they are willing to hold it for long-term, however, I believe everyone's financial goals and strategies are different.
ETH is an altcoin that is suitable for both long-term and short-term investments because you can see it being very volatile from time to time, and when a cryptocurrency is so volatile, you can use it for short-term gains, and if the same cryptocurrency is also old and trusted, it can be used for long-term holding because you know it won't deceive you.