I use & love Firefox, too, but do note that the author's criticism directly applies to it, too: AFAIK, FF will not show you the individualized cookies, or all you to act on them individually.
Now, as you say, you can download an extension (and indeed, I do!), but I think there is some merit to it being in the base app. (E.g., not having to trust an extension. But also, it's part of Firefox's data, and FF should provide decent tooling for itself.)
That data is available in the developer tools, under the Storage tab. Individual cookies can be viewed, edited, and deleted. Not very useful for the average user, but the option is there and I doubt the average user even knows what cookies are, except that they're something you constantly have to click "yes" to nowadays.
I'm running the latest developer build and it still has this. It only shows number of cookies by domain and allows deletion by domain, and you'd have to use dev tools if you wanted to look at or delete a single individual cookie.
> I'm running the latest developer build and it still has this.
Hmm, are you sure about that? IIRC, Firefox 90 had ability to remove cookies per exact subdomain in that view (i.e. account.google.com), since version 91 there's only an option to remove cookies for whole google.com domain...
Now, as you say, you can download an extension (and indeed, I do!), but I think there is some merit to it being in the base app. (E.g., not having to trust an extension. But also, it's part of Firefox's data, and FF should provide decent tooling for itself.)