I realised a long time ago that even shedding merely a single tear every time an evil deed is done would lead to dying of dehydration in one's sleep.
I mostly try to cut out the news, but the options are not limited to just cutting it out or becoming cynical: an ex went into politics with a genuine desire to make the world right. She is (or was) Green Party (US), so not making much progress, but it is at least a different path.
I definitely agree our minds aren't fit for this world: more people online than heartbeats in our lifetimes, combined with a psychology that treats a list of more than 7-ish items as infinite.