It's not and that's the reason why the author doesn't address it in their article. It's just bad faith.
Especially with CSS pre-processors (because they make writing that syntax in the CSS file super easy) which basically everyone is using, ".card.card-big" is the obviously right solution.
It is easy to read, specific, doesn't risk collisions, doesn't risk adding broken styles if you forgot the "card" class on the element, etc. It addresses all the negatives outlined in the "BEM is not the solution" section of the article.
The only "argument" that still sticks against this one is that "it's verbose", but not once in my career have I seen a __good__ software engineer discard a perfect solution because "it's verbose".
Especially with CSS pre-processors (because they make writing that syntax in the CSS file super easy) which basically everyone is using, ".card.card-big" is the obviously right solution.
It is easy to read, specific, doesn't risk collisions, doesn't risk adding broken styles if you forgot the "card" class on the element, etc. It addresses all the negatives outlined in the "BEM is not the solution" section of the article.
The only "argument" that still sticks against this one is that "it's verbose", but not once in my career have I seen a __good__ software engineer discard a perfect solution because "it's verbose".