Ethereum is a good known project in the cryptocurrency industry. Ethereum (ETH) is a safe cryptocurrency to invest in because eth is the 2nd largest cryptocurrency in the world. So, its so much stable & its price will be increasing.
Of course ETH is a safer asset, just like bitcoin, but some altcoins can bring much more profit with less investment. I know from my own experience, that it's a shame to see the whole market growing and ETH or BTCs growing slower. But if I consider long term investing, I would buy ETH.
Bitcoin and Ethereum develop not slowly, it can be said that both are the 2 coins that bring the biggest profits in the market if you invest early. If you invested in them in recent years, you can't blame them for their slow growth, but rather that you didn't invest in them early. The larger the cap, the smaller the profits will be, but they will be safer compared to small-cap coins. There is no investment that is both highly profitable and safe, don't become greedy like that.