How is this better than blocking all third party content with uBlock Origin? Doing so does break a lot of websites, but you can always manually enable necessary CDNs if you care.
I doubt Privacy Badger blocks fonts.googleapis.com for example, which is a dependency A LOT of websites have and that allows Google to track people across the Internet.
Privacy Badger has three modes for each host (other than the origin) from which content is loaded on a page: Allow, Block Cookies, and Block Entirely. This lets you load things like Google fonts without allowing tracking cookies to be set. Yes, Google still sees your IP and user agent and can do some tracking that way, but they can't add a tracking cookie (at least once Privacy Badger sees them trying to), and you have the option to block Google Fonts (and whatever else) entirely if you want.
PrivacyBadger adjusts what it blocks over time vs seeing it track you. It did start blocking Google Fonts for me, and I had to manually re-enable it because I wanted it.
I forget which level of blocking it was applying; some cookies it just keeps from being cross-site, it isolates them. Others it blocks entirely. You can easily adjust which it is doing for any given cookie.
I think it's true that if you have uBlock Origin you probably don't need this though, that seems likely. I don't run uBlock Origin.
I doubt Privacy Badger blocks fonts.googleapis.com for example, which is a dependency A LOT of websites have and that allows Google to track people across the Internet.