> The “problem” we have today is that too many different commentators
No, the problem is the so-called "democratisation" of journalism and the corresponding cross-fade between "shill", "pundit" and "journalist". It's not the diversity in voices, but rather the lowering of the bar. Any random YouTube hack can proclaim themselves a "journalist" or "commentator", regardless of their credentials or affiliation.
Meanwhile, traditionally trustworthy media channels are trying to be "fair and balanced" by including both sides in a debate, regardless of whether both sides are sane. Think anti-vaxxers, Holocaust deniers or flat earthers versus their rational counterparts. Then there are more complex issues like "stolen" elections and Brexit.
This "both sides", "marketplace of ideas" approach also stimulates polarisation, making everything a partisan issue, especially in politically bipolar countries like the US or the UK. Suddenly, even well-accepted facts are "controversial", generating clicks because all that matters is engagement.
> Others will look at those they disagree with, and say they are spreading misinformation
That's a very modern (as in, post-modern) take. There is no denying there is a lot of actual misinformation on "both sides". It's not so much who you disagree with, but journalistic integrity, of which I frankly don't see a lot, regardless of whether we're talking about the Guardian, New York Times, Washington Post, the Independent, Fox News, Newsmax or OAN. They're all mainly pushing an agenda, during which they at least lie by omission. What's more, they no longer distinguish between OpEds and news reporting.
> free democracy, and having an arbiter of truth are mutually exclusive states
That's a false dichotomy. There doesn't need to be a single arbiter ("Ministry", if you will) of Truth. The purported added benefit of the fourth estate is its many voices would each do their part in verifying the veracity of claims and elucidating the context of events.
It's required for a functional liberal democracy because powerful voices can otherwise dominate the narrative and peddle messages like "regulation is at odds with a functional economy" or "fact checking our statements implies bias". With the number of journalists decreasing by 75% in the US since the advent of the Internet, the fourth estate has obviously become increasingly dysfunctional and shallow.