No, GDPR quite explicitly plans for that.
First, there's no such thing as "click consent buttons in order to use the websites they want to use" - if clicking that button is needed to use the website, then it doesn't count as freely given consent. I.e. either the choices are "Agree and proceed" and "Disagree, but still proceed" or you might not have bothered with asking, since that click is not consent. If the data is not inherently needed to provide the service (i.e. a delivery address if you want something delivered), then users must have the option to refuse.
Second, there can be no single "consent to do everything". You have to explain every single usecase separately with details and specifics, and get consent for each use case separately. This is a big issue. If a small company has something particular in mind, it's not a big deal. But if a megacorp has (had) a habit to use your data everywhere for everything, that's not going to work. As GDPR states, “A purpose that is vague or general, such as for instance ‘Improving users’ experience’, ‘marketing purposes’, or ‘future research’ will – without further detail – usually not meet the criteria of being ‘specific’”. If the list of use cases and their details doesn't fit on a single screen, users simply won't accept them. For an organization like Facebook, it'll be a major challenge to simply list the places and ways where they are already using my data - and they'll either have to give that full list to me and somehow convince me that I should agree (as the default option is to refuse with no consequence to me) or stop doing it.
In essence, you have to bring them to the privacy dashboard first. And everything has to be opt-in (default off). If you have a random consent button like the classic "Agree" under terms and conditions - well, that doesn't count as informed consent, so if that was your system then you don't have consent from any of your users, and your use of their data was prohibited. Even if most users won't care, a few activists can force you to change the behavior for everyone or risk major fines - i.e. if I see that you're using my data without my consent, then it doesn't stop at you removing my data; the regulator can ask you to prove that you got informed, specific, freely given consent from all your other users.
Third, previous consent doesn't imply future consent - if you want to use the data for something new, previously this was done by quietly amending the terms and conditions, and adding a new option to the privacy dashboard (often pre-selected). Under GDPR, every new use requires new consent.
Fourth, a lot of the tracking has historically been done by third parties. I can see myself giving consent to use my data on some forum or blog that I frequent; however, the consent that I give them doesn't count as consent for all the ad networks running the ads on their site. The ad networks would have to ask permission separately (which they won't realistically get, ever) and they also can't count on getting the site owner to give them my data, since site owner needs my (separate! opt-in! specific instead of "may share with third parties"!) consent for that.