I understand what you're saying. I honestly think that the truth lies somewhere in the middle of a field of variables (full disclosure: I used to work in software for a news org).
Firstly, there are reputable outlets out there covering alternate angles of the Ukraine conflict, like Aljazeera[0], but they can be hard to find. One of the biggest problems I see with curation generally is that it makes people lazy and not take the effort to find the outlets that are providing counter commentary. Just because you're not seeing a particular perspective being covered doesn't mean that isn't. I think there's a much bigger discussion to be had around the efficacy of curation because it very easily leads to this bias.
Second, media companies are businesses, and like any business, they give and receive influence based on a variety of internal and external factors. For example, it's well-known that organizations like AIPAC lobby on a variety of fronts to push particular agendas, which can easily skew perspectives on certain issues (like the double standard between how we see Ukrainians and Palestinians). This is a consequence of America's embrace of lobbying.
Third, media companies are becoming more reactionary than ever because they now have data on what kinds of stories get clicks in ways that they didn't 20 years ago. In an ad-driven world, you bet media companies are constantly looking to see what kinds of content drive the most traffic to their site.
I think we are seeing patterns emerge that do drive homogeneous, coordinated behaviors on the part of media companies, but I don't think it's as simple as nefarious government-driven propaganda. I think there are many interests, public and private, which vie for particular narratives and stories via lobbying in the exact same way that companies bid on ad space via Google Ads, because its perfectly legal to do so.
One could argue that public relations firms are professional propaganda creators depending on your viewpoint.
0: https://www.aljazeera.com/news/2022/2/27/western-media-cover...