While I agree with you, I wouldn't call it meaningless though. I think people just take the marketcap statistic a lot less seriously, as it's definitely quite inaccurate. I think it's a decent statistic to use when ranking probably only the top 20 coins/tokens when determining which coins/tokens are more "valuable" in terms of market value.
but it IS meaningless. specially when you are talking about value of a cryptocurrency and want to use it for ranking. value of a coin should not be determined by how much supply it has, no matter how high or low it is in some arbitrary ranking. what you should use is their utilities and a lot of other factors such as decentralization, number of nodes, number of transactions, number of merchants,...
and while we are at it we shouldn't even rank coins that are not even similar. we should categorize them and then rank them. for example centralized coins should not be in the same ranking as decentralized coins. or tokens (like ETH, Waves,...) should not be in the same category as currencies (bitcoin, litecoin, IOTA,...)