That is not correct. Here's a more complete quote:
> uBlock Origin is NOT an "ad blocker": it is a wide-spectrum blocker -- which happens to be able to function as a mere "ad blocker". The default behavior of uBlock Origin when newly installed is to block ads, trackers and malware sites
There is nothing here indicating that uBO "mainly" blocks trackers. It blocks malicious content which includes ads. The quote even suggests that it does primarily block ads as that's what people care about and install uBO for.
> uBlock Origin is NOT an "ad blocker": it is a wide-spectrum blocker -- which happens to be able to function as a mere "ad blocker". The default behavior of uBlock Origin when newly installed is to block ads, trackers and malware sites
There is nothing here indicating that uBO "mainly" blocks trackers. It blocks malicious content which includes ads. The quote even suggests that it does primarily block ads as that's what people care about and install uBO for.