Relying solely on uBlock/uMatrix also have limitation because of how Firefox loads its add-ons, it won't block connections on first startup because the browser gets to connect before the addons fully load, so if your homepage is DuckDuckGo, you're probably in the tracking clear, but if you use another landing page or a random saved tab loads, some tracking might "get you".
It also won't cover your other add-ons from collecting your data, if you use firefox then you probably use add-ons, I consider many "must haves" but even despite them being open source on git-hub, and highly reviewed, they still do some "collecting", which I'd rather opt-out of but can't because no option to do so, so the only way is to use a hosts.
For example add-on
Violentmonkey.
"We may use Google Analytics to collect your browser information anonymously to help improve compatibility." Nah, no thanks.