I’m 100% sure there are massive propaganda (lies, hoaxes, half-truths, finger-pointing) campaigns funded by states themselves, either to keep their own power, or to get more power in other states. How does one fight them and not feel like it’s not worth the effort?
You can’t, all by yourself. At least not in the same scale. Fight them in conversations with people in your life whom you can reach when they repeat misinformation. That’s all you can do unless you are motivated to get involved in politics or journalism.