I think that "the government buys things that it uses" isn't inherently corruptive.

In this specific case, Politico is apparently worth over a billion dollars based on its sale in 2021, so I think that the US government giving it $8M would be a shit bribe and insufficient to hurt its independence. Based on its subscriber number boasts, it's getting at least $350M in annual subscription revenue. (Probably more, since I'm assuming the cheapest subscription there.) Would they care about a 2% drop in subscription revenue? Likely not enough for it to affect their coverage.