Your test is irrelevant. There is always going to be some tiny percentage of ads that passed through with any ad blocker. So the fact that you have seen ads passed through with it doesn't actually mean anything.

The only thing that means anything is how well it operates with your average browsing on a daily basis. And it's such a popular extension because it does an amazing job at blocking ads. That's just a fact. The only people who seem to claim otherwise appear to be the ones with an ideological axe to grind. It's silly.