This is a rather facile answer to an important question and one that can be easily gleaned from the Op-Ed pages of The Guardian. You fail to mention the ownership structure of the media and how this impacts its editorial decisions, its access to resources and the proliferation of unpaid internships and insecure labour practices that exclude most people but the independently wealthy from entering the profession.
With regards to your third point. Since when has disinformation been the sole purview of government funded media? The ongoing campaign by the Murdoch consortium against peer-reviewed science in the field of climate change is surely the most obvious example of disinformation and a highly successful one at that. Furthermore, with regards to your second point on false balance, you failed to bring up the most salient issue of climate change or international relations. In the latter, for example, it is common practice on TV news to present two "analysts" that agree in principal on a subject but share a difference in methodology. To illustrate, that will be a discussion on what should be the most appropriate approach to dealing with the Syrian civil war with "regime change" in Syria being one position or "just" a no-fly zone the other without the position of those opposed to military solutions (let alone the Syrian government) being presented.
That certain media outlets have found such receptive audiences in the West is because, in addition to instances of disinformation, they cover stories that are excluded from the mainstream media discourses due to the editorial decisions at newspapers and TV news that has much to do with the personal biases of management as it is the influence of a concentrated ownership structure. To return to the example of climate change once more this is an issue that should be front page news in all outlets yet it is consistently regulated to back pages in favour of political gossip of no consequence or fails to be mentioned in articles about the economy. Further, it came as an embarrassment to outlets like MSNBC and NYT that it was RT America that extensively covered the Occupy Movement when it emerged when, for weeks, it was practically ignored thus enabling this government-owned outlet to gain influence and audience share in the US.
There are legitimate concerns about the "Fourth Estate" and I think one should trust the layman's observation that in the West, especially in the English and Spanish speaking worlds, it is utterly dysfunctional in terms of its theoretical role of keeping democracies honest. Your first point about "increasing partisanship" overlooks the rich history of conflict between the "newspaper barons" and the labour movement in the UK and US whereby the newspapers were often seen as crucial areas of political contest, which belies the notion that partisan news is some kind of novel phenomenon. Indeed, this idea that polarisation is an exception and not the norm is merely part of liberal political theory that is true in some circumstances but usually not in most. The decline of the free press in Italy in the 20s and Wiemar Germany are instructive because it was the fascists that argued that partisanship in the media was damaging to the "national ethos" even though their newspapers were no less partisan than those of their opponents.
Perhaps, what we are witnessing in the West is a wising up among Westerners from the fog of Cold War era propaganda that their news media institutions were honest brokers of the Truth untainted by material self-interest or partisanship. To use a quote attributed to Zdeněk Urbánek:
"In dictatorships we are more fortunate than you in the West in one respect. We believe nothing of what we read in newspapers and nothing of what we watch on television, because we know it's propaganda and lies. Unlike you in the West, we've learned to look behind the propaganda and to read between the lines, and unlike you, we know that the real truth is always subversive."