That's not compliant with the GDPR plain and simple. For example ads on a website are not required for that site to work (even if it's the only revenue), so the site cannot store data only to track users to show ads. The way a complliant site should work is it can say
"if you want to allow tracking cookies to get more relevant ads you can do so in settings".
I.e. no must be default in case of non-acceptance - and the site must still function.
Hopefully they will be fined huge amounts of money.