Two answers to this, one cynical and the other practical. Cynical answer first.
The media is biased, always has been, always will be. The bias can be small, but it's noticeable and there. That's why conservatives read Fox News and liberals read Huffington Post.
Another way to have bias is to decide what to report on. It's why when Crimea voted to join Russia, Western newspapers focused on how the referendum was not free or fair and interviewed Crimean Tartars, while Russian newspapers focused on how Crimeans are overwhelmingly in favor of joining Russia & demonstrations in other parts of Russia in support of Crimea joining Russia. It's why Western newspapers use the word '"annex" and Russian newspapers use "ascension". Both report facts, but both push a different narrative.
You see something similar with Saudi Arabia & Afghanistan. Western newspapers want to push the idea that the Taliban are evil people who repress women, hence they report extensively on Taliban atrocities and interview women who do not like Sharia law. Note they don't interview women who are happy to live under Sharia law or think Sharia is correct (I am sure some exist, since there are women who wear full-face veils even in countries that don't require it). Western newspapers don't want to push the narrative that the Saudi Arabian leadership are evil people who repress women, hence they don't report it (at least not right now).
Ultimately the newspaper needs to earn money, and to do that it needs to report on what its readers want to read about. Sometimes an event is so major that everyone has to cover it, but other times there is room for discretion. This is when editors of newspapers can be biased (above in the cynical answer).
On the other hand, you can be sure that the editors are also monitoring what their readership are doing. If the articles on Afghanistan generate a lot of clicks, then they are in demand, and the newspaper would quite sensibly keep reporting on Afghanistan.
In practice the two factors kind of intertwine. If a Western newspaper were to start reporting that Afghans are actually happy to live under the Taliban,* then because most Western readers want to believe the Taliban are evil, the readership would move en masse, and the paper would lose money. Equally, the editors of the newspaper want to believe the Taliban are evil, so they are already biased to keep up with kind of reporting. It's an unholy alliance that keeps the media reporting on what it's reporting.
The upshot is people become polarized because they read different newspapers; there are plenty of examples worldwide.
*I have no idea if this is true, but given that answer, it's possible.