Content blockers like uBlock use filter lists which list every single element that needs to be blocked across the entire web. I currently have nearly 700000 of these filters active. That is very far outside the scope of a simple script. Basically all ad blocking userscripts are site-specific and they still usually block significantly less than uBlock would on the same site. Also, userscripts are not safer than extensions.
Firemonkey is open-source, random scripts can easily be inspected. I know performance probably will suck, but I know the code being run don’t monitor me. Can you say the same for uBlock?
uBlock Origin also does a lot more than just block request, I’m not sure features like cname uncloacking would be feasible as an userscript.
Ublock is also open source. So you also can see what it’s doing. So yes, you can say the same thing about ublock
