> On Mac at least, I'm not aware of any viable non-Chromium alternatives
Surely Mac is the only place there is a viable non-Chromium alternative (Safari)?
I think people like to imagine it's not viable because the most commonly known adblocker refuses to release the version for it. Negative news somehow stick better.
Fortunately it's not the only one and for example Adguard works perfectly fine.
There is Orion which is built on top of WebKit so you get a lot of the battery life optimisations built into Safari