https://github.com/gorhill/uBlock/wiki/How-to-whitelist-a-we...
People seems allergic to browser extensions this days. I also get the "why is this an extension and not a filter?" on a non ad-related extension.
Extensions are also vectors for adware and malware so it's better to trust established extensions, and questioning an extension whose behvior could be trivially accomplished without is a reasonable concern to raise.
That's why I'm skeptical of new browser extensions for things that the ones I have can already cover.
Doesn't mean everybody else has to feel like that (e.g. I honestly hadn't considered someone might want to install this but not a generic configurable blocker - even if you aren't aggressively blocking ads uBlock would be useful for me)
Using a different addon for exactly the same purpose but for different content is the worst kind of separation of concerns.
Ad blockers have their own issues, including trust about maintainers intentions.
There are blockers which can use lists, some of those lists might contain ad domains, some of those lists might contain miner domains.