I have been using it for about a year. There is zero advertisement anywhere. No sponsored posts. Just pure search. And they give you quite some good tools to derank or delist websites for you to define your own quality of search results, it’s very effective. They also go the extra mile of de-ranking websites with many trackers as that apparently correlates with SEO which normally doesn’t track with result quality. It’s a very refreshing take on the web. I love it :)

Edit: they also have an extension which allows you to search while being logged out using tokens which improves privacy, in case you want to go the extra mile.