system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: computer browser adblockers are amazing yet every single phone adblocker can't do anything, whys that

I had a rooted phone with adaway and it still wasn't enough to stop ads from my phone. Clicking on something would constantly open another tab to another site telling me I had a virus and making my phone vibrate. Especially from file downloading sites. 

Yet on my pc both chrome and Firefox cannot be cracked with ublock. Haven't seen ads on my pc in a long time.
gpt
AdAway blocks advertisements by redirecting known sources of ads to localhost - essentially a /dev/null solution. The reason this is the preferred method on Android is because many devices are limited in what resources they have available - especially lower end or older phones. Additionally, these less powerful phones are the ones more likely to be AdAway users, because adverts also consume resources.

However, if an advert comes from a source that is *not* already known, it will not be redirected to localhost. For this reason, it is important that you regularly update AdAway, as it does not automatically do so.

Another point to consider is that AdAway *doesn't always work*. Rooting methods change from phone to phone and ROM to ROM. In fact, it may be entirely possible that the hosts file is not actually modified at all.