Yes! Disable 3rd party cookies, delete your Google & Facebook accounts, and done. Easy peasy.
I wish that was enough. The articles that show up here on HN from time to time make me think they can cross-reference data and fingerprint you through many data sources and more advanced tracking (things that we discover from time to time like canvas, css). People that have you on their contact list, your e-mails that hit their servers even when you don't have a Gmail, DNS, CDN, cloud services, your phone unless you…
It’s not. While Facebook will exfiltrate and cross reference your name and number from associates’ address books, this wildly different than keeping a log of everywhere you travel, the time you wake and sleep, hundreds of tagged images of your face, all the news you read, and how readily you can be influenced. Primarily to influence your mind and behavior for profit, but all available to international governments to keep and eye on you, too.
I agree that Facebook and Google are too powerful, and that there should be much better protections around consumer data. Support the EFF, talk to your representatives.
Fatalism serves no one but Facebook and Google.