> GDPR requires consent to be freely given. If customer A rejects the terms and you "walk away" and deny the service, then if customer B clicks accept, you still can't interpret it as freely given consent and nothing customer B does will give you the permission to process customer B's data.

Are we conflating two things here?

There are agreements which you ask the customer to sign which are required to provide the service: e.g "In order to send you the goods you required, you have to give us your postal address. These must only be used for the purposes of the business - you can't sell the addresses, without consent.

Then there are consents which are for non-essentials. e.g "We would also like to send you our newsletter and for that you need to give us your e-mail address".

The agreements are things that everyone needs to sign in order for you to carry out the business with them. Consents are the optional things and should be separated out.

Or am I misunderstanding you?