maybe ... just a thought .. but, don't agree to them?
it should be just as easy to agree as to decline. if not, then they are likely not adhering to the regulation, and eventually someone will/could alert them or whatever authority.
And the whole practice of huge scary obtrusive modal-like dialogs (that tint the background so you can't even read it normally) are the cheap tricks used by sites to incentivize you to consent to tracking. So, it's almost certain that those are not compliant. They replace the fundamental function and purpose of the site with a fake choice.
Specific things that require data and/or cookies to function (e.g. providing a shipping address so that your package can arrive) are exempted, obviously. But everything else is supposed to work, regardless of consent or not.
This is due to Art. 7, Paragraph 4[0,1] regarding "Freely given consent". If your only option is to consent, or not use the website, your consent is not freely given.
[0]"When assessing whether consent is freely given, utmost account shall be taken of whether, inter alia, the performance of a contract, including the provision of a service, is conditional on consent to the processing of personal data that is not necessary for the performance of that contract."
it should be just as easy to agree as to decline. if not, then they are likely not adhering to the regulation, and eventually someone will/could alert them or whatever authority.