[Saaster]

It's a common misconception, but consent is only one of the 6 recognized lawful basis for processing specifically recognized by the GDPR, and a company may contact you when any one is applicable. For example, if you have an existing business relationship via a contract (you bought something), or the business has a legal obligation to inform you of changes, or the nebulous "legitimate interests" basis on behalf of the business.

Those emails which ask you to click to continue to receive marketing are a red flag that those companies did not have any legal basis previously, or they're just cargo-culting other companies even though they already have a perfectly valid basis to keep in touch (like you being a an actual customer). Check out your favorite big-company SaaS signup today (like, Jira), you will still typically not see any explicit consent checkboxes, because due to a customer relationship it is not needed.