I will consider ADA as something really good and deserve it's place in the coinmarketcap. But Ethereum just outclasses cardano in every aspect that is why you should consider holding more Ethereum than ADA. But ADA is still a good choice for long-term hold.
ADA is a good investment for long term, same with ETH, but as an investor, know the project and it's roadmap so you can analyze properly their potential to grow in a certain period. The market has a wide variety of good projects and we can choose among them, but choosing one is not wise and I'm sure people will choose ETH over ADA since ETH is in the rank 2 now, but that rank is not permanent, so better know how to diversify so you will not miss the opportunity.