> But if cookies are disabled, then there's no point in asking for consent.
But the only way to determine if cookies are actually disabled in the browser is to attempt to store cookies, which is the thing you're asking consent for.
Not really, there's also navigator.cookiesEnabled now.
And even if there wasn't, attempting to store a cookie with a dummy value just to check if cookies are enabled does not break the GDPR for three reasons: first, if it's a dummy value it's not really personally identifiable information. Second, it's a functional cookie required for the site to work. And third, the site can just delete it afterwards the checking. No consent required in this case.
But the only way to determine if cookies are actually disabled in the browser is to attempt to store cookies, which is the thing you're asking consent for.