Furthermore, if I remember correctly, no explicit consent is required where the cookie has to be used for features the user requested, like a shopping cart.

So, if the law was actually written to require what it was supposed to require, and actually enforced, a web site operator would have the options to either:

a) implement an opt-out globally across the entire site to ensure no part sets a cookie and doesn't track them, with a high risk if you get it wrong, annoy every visitor with a modal yes/no before letting them onto the site (which would hurt your conversion rates etc.), where the "no" would be a meaningful choice that would still let them use your site, and there would be very little incentive for the user to click yes

b) stop tracking users unnecessarily in general

As it is written, the options are:

a) implement an opt-out globally across the entire site to ensure that no part sets a cookie and doesn't track the users, with a high risk if you get it wrong

b) slap an annoying banner on your web site

One of these options is significantly less work and allows you to keep tracking users, so guess what gets done.

From what I understand, the GDPR also disallows denying users access to a site if they don't consent to an unrelated data collection.

Before accessing the website, you get a choice between yes and no.

If you select no, the site will not do any tracking, no analytics — some sites disable ads in that case entirely. You still get to access the site.

If you select yes, you getthe tracking.

[0]: https://en.m.wikipedia.org/wiki/Standard_form_contract

There is currently no detailed description as to what the definition of "sufficiently" is. For example:

- can I use your data to build a targeting machine learning model?

- can I use it to target you?

- do I need specific opt-in for every model?

Most things in GDPR are not specified in order to both give flexibility to the sites and to reduce the number of loopholes (which are technically legal but against the spirit of the law). You need to decide on the implementation and be ready to defend it in case of an audit.