A language preference cookie is not tracking under the GDPR and doesn't need to be promoted for. Of course, if you take that language preference and feed it into your advertising to identify and target people, then it becomes tracking.

>The law requires consent before using a cookie to store even a mundane option that was just directly modified by a user.

If your are referring to GDPR this is wrong. GDPR does not require consent for strictly necessary cookies.

>Strictly necessary cookies — These cookies are essential for you to browse the website and use its features, such as accessing secure areas of the site. Cookies that allow web shops to hold your items in your cart while you are shopping online are an example of strictly necessary cookies. These cookies will generally be first-party session cookies. While it is not required to obtain consent for these cookies, what they do and why they are necessary should be explained to the user.

https://gdpr.eu/cookies/

Though language preference does not seem like something that requires a cookie. Just respect the Accept-Language header. There is no need to reinvent the wheel here.

> The law requires consent before using a cookie to store even a mundane option that was just directly modified by a user

Nope.

That's exactly why the evil cookie modals are not on the GDPR but only on the sites that want to track you and now need to ask you for your consent before doing so. That's usually exactly where good faith GDPR detractors are wrong, and that's what needs to be repeated again and again in those discussions.

Accept-Language.