Page A loads content for X seconds and Z seconds loads ads. uBlock overhead is Y second but saves Z seconds by blocking ads. Total time with uBlock is X+Y-Z. If page has zero ads the time will be X+Y-0 which is greater than X+0.
Yes. Pages with ads are unreadable. I'm horrified every time I see friends navigate with no adblockers. I always recommend one. I'm going to start recommending Firefox again, as I did at the times of IE6.
Presumably because uBlock's baseline overhead is approximately 1 second. Therefore on other sites there is enough overhead from ads or tracking that it is still worth it to use uBlock.
Here's evidence[1] that uBlock adds less than 100ms to "an atypically large page from a nice site" (i.e. one that doesn't have any ads). Some other effect is at work here, it's probably just random network latency differences.
So it has 1 second of startup cost? I have a hard time believing uBlock would add that much time to every request. Ideally this would make a more realistic measurement that doesn't include startup cost.
