uBlock Origin is not an "ad blocker", it's a wide-spectrum content blocker with CPU and memory efficiency as a primary feature. Out of the box, uBO blocks ads, trackers, coin miners, popups, etc. through the following lists of filters, enabled by default:

EasyList (ads)
EasyPrivacy (tracking)
Peter Lowe’s Ad server list (ads and tracking)
Online Malicious URL Blocklist
uBO's own lists

More lists are available for you to select if you wish:

EasyList Cookie
Fanboy Annoyances
AdGuard Annoyances
Dan Pollock’s hosts file
And many others

Additionally, you can point-and-click to block JavaScript locally or globally, create your own global or local rules to override entries from filter lists, and many more advanced features. Free. Open source with public license (GPLv3) For users by users. If ever you really do want to contribute something, think about the people working hard to maintain the filter lists you are using, which were made available to use by all for free.

Documentation
Release notes
Community support @ Reddit
Contributors @ GitHub
Contributors @ Crowdin