Is Drupal ready for GDPR compliance?
I'm one of the maintainers of the GDPR module.

First of all I'd like to call your attention to the fact that GDPR is not an IT-related question solely. Personally I'd suggest stop considering "adding an extension to my CMS will make me legally good". That's not that easy. You, or the owner of the Drupal website you maintain/develop on their behalf should transform their organization/company's inner workflow of dealing with personal data.

However, the GDPR module indeed can be a perfect starting point to install, go through on its checklist points and after you read them carefully, hopefully will realize that you're just stepped on the path of becoming GDPR-compliant, but a big portion of tasks ahead probably falls out of the scope of configuring Drupal.