My investment investment now is only in Bitcoin but might be diversify or extend my investment to another projects but not now. The altcoins are still under my watchlist. And I will invest when altcoins market is interesting me to invest as for now they are not. Let me focus on Bitcoin for some period and when the altcoins move upward to the stage that is good to invest and I have interest to invest then I can do that.
Ethereum as others have said it would have been the good altcoin to invest but it is not doing well for now.
Also, I see your second option which is Ethereum as moving around a circle, as Bitcoin and Ethereum will always be moving in almost the same way. They will earn almost the same multiples of income for you or make you lose in that same magnitude as well. This is why I have Bitcoin in my arsenal and avoided Ethereum, but only invest in altcoins that do not have many similarities to Bitcoin when it comes to the way they behave during their selling and buying times. Although, I trade Bitcoin and Ethereum all the time on the futures market, but on investing them, I am so careful not to waste my time while my money is being wasted with them when other altcoins are seriously performing well. What a waste would that be.
I was also all about Bitcoin, investment alone when I first entered into the crypto space, this is because I was cautioned about the risks of scams in altcoins. But now that I have increased my crypto knowledge, I can make my own research and invest in profitable altcoins because as an investor I should be profit-oriented, and it's not too profitable for all my funds to be in one cryptocurrency. Bitcoin is undoubtedly the most reputable and trusted cryptocurrency, but there are other cryptos that have also built reputation and trust in the crypto market, which will make investing in them a good business decisions. Despite what Ethereum, is at the moment, it remains a very trusted crypto coin.
The altcoins that I trust most is Ethereum, at the top, BNB Solana and Shiba Inu, I choose them because they're still relevant in the crypto market and I believe that they have potentials to be bullish in the alt season. Then there are other numerous projects in the market that can give profit on the short term, but investors needs to understand that investing in most of them are gambles, so DYOR.
That's the spirit! Diversification is key in investments, especially at this time when the price of Bitcoin is heavy enough. We should think of how we make more money (but also in a safe environment) rather than believing that it is Bitcoin alone that can do it. Those who have been diversifying their portfolios since last year who know how much they make in multiples of what Bitcoin long-term holders have made, which is the gist here, it is all about the money unless we are deceiving ourselves.
However, my situation was a bit different from yours when I started investing in cryptocurrency, and as a matter of fact, I joined Bitcointalk before I eventually started with crypto investment. But I've known about cryptocurrency for many years before then, and if I am correct, I have known cryptocurrency since 2013 or even before then but I never invested, I was just using it as a payment system which I still regret today. When I started the crypto investment, I was only buying Bitcoin for months, which was the aim though. But later, I started diversifying when the price of Bitcoin was high and discouraging to me enough, I think this was smartness and I have never regretted my action till now.
Before I go, just some advice, you need to look lower than the top-rated coins to maximize your profits, the world of crypto is evolving gradually. So to make more money, you might want to try the popular Memes, Defis and newly introduced L1/L2 projects. I also like you to focus on TON projects, I think Notcoin has paved the way for that.