You're correct under the GDPR but incorrect under the older ePrivacy Directive. EU sites need to be compliant with both, and so the cookie banners persist.
https://en.m.wikipedia.org/wiki/EPrivacy_Directive says
> The Directive provision applicable to cookies is Article 5(3). Recital 25 of the Preamble recognises the importance and usefulness of cookies for the functioning of modern Internet and directly relates Article 5(3) to them but Recital 24 also warns of the danger that such instruments may present to privacy. The change in the law does not affect all types of cookies; those that are deemed to be "strictly necessary for the delivery of a service requested by the user", such as for example, cookies that track the contents of a user's shopping cart on an online shopping service, are exempted.
> Cookie compliance [heading]
> To comply with the regulations governing cookies under the GDPR and the ePrivacy Directive you must:
> Receive users’ consent before you use any cookies except strictly necessary cookies.
(emphasis not mine, but would have added it)
A language preference cookie is not tracking.
The GDPR is different from the ePrivacy Directive. The EPD is responsible for cookie consent. And it has the language addressing preferences cookies.
But I see what you are saying now. That page lists the different purposes, including preference cookies (which include language preferences) and strictly necessary cookies, and I know asking consent is not necessary only for strictly necessary cookies (this page says it, I quoted that part earlier).
If that page is right, you are right and I was wrong. Thanks for persisting.
Well, that would be a shame, and that probably would explain why cd.cz makes me pick English each time I visit. I was assuming they could just save this preference in a cookie, but they obviously wouldn't be able to since I didn't provide consent, since I hide the cookie banners and they don't ask for consent later when needed.
Now, that page is not authoritative and I see it criticized here: https://www.reddit.com/r/gdpr/comments/vniefz/strictly_neces...
I guess it it safe to ask consent in doubt, but I'm not yet convinced the language cookie cannot be considered strictly necessary. How can you correctly provide a requested service to a user if you don't use a language they understand, and how storing the language is not for fulfilling an explicit request from them?
It's easier and safer to just claim that you must prompt for everything, and it serves the goal of obfuscating bad behaviour.
Cookies that are functionally necessary to do what the user is there for, not to track them, are OK, that's the spirit and intent of the law. Even if you think the wording means that, realistically, the EU isn't coming after anyone for a legitimate good-faith use of language cookies without a banner, and they'd clarify if that was how they intended to enforce it.