Because I read all kinds of news, and have conversations with all kinds of people with all kinds of viewpoints, and I’ve come to recognize the very strong concordance that exists between on the one hand “it’s all the West’s fault anyway / Ukraine’s just as bad if not worse when it comes to (whatever we are talking about)”, and then combined with that on the other hand a general pattern of lying, bad-faith argument, awful sources, or just vanishing like a fart in the wind whenever someone challenges their viewpoint.
Also, how do you know that it’s just as bad on the Ukrainian side? For one thing, they didn’t start the fucking war, so who would care what they do to invading soldiers who have no business being there anyway. But even regardless of that, they have nothing approaching the level of Russian brutality towards POWs and random civilian prisoners. Some details are in the OP article. Why are you claiming that they do?