For a growing number of users, we can provide search results and ads from Google. For the eligible users, we will provide Google results by default. When your search results and ads are provided by Google, Google will use essential cookies and local storage to help defend against fraudulent traffic. Beyond this, the cookies Google uses will depend on where you are searching from: If you search from the EU, UK or certain US states (for example California), Google will not set additional cookies without your consent. If you search from elsewhere, Google may place additional cookies and the functionality of these cookies will depend on whether you have a Google account

Seems like using Ecosia is about as private as using Google directly.