Thank you, nomics.com looks good to me. At least I can start with that. I can say you've answered my question.
As far as coindesk is concerned they've got a serious problem. At the current price and circulating supply, it would be incomprehensible for the website not to list Cardano in top 20 or even top 10.
That's because they rank based on volume, not market cap. They look only at exchanges with "verifiable" volume data, then they rank coins according to volume. Also, if a coin isn't traded on two spot exchanges among Bitfinex, Bitflyer, Bitstamp, Coinbase Pro, Gemini, itBit, Kraken and Poloniex then it doesn't make the cut.
Until 3 days ago, Cardano was only listed on Kraken. Now that Bitfinex just listed it, it might make the list. I'm too lazy to confirm by the volume numbers.