If I get the time I may add my comments here, but in short: Getting serious union support (money) for left media is a great idea. The more unions are democratized and the more radical they become, the greater chance there is of that happening.
The thing that’s missing is an organized left. Could Momentum be turned into an activist movement that doesn’t just advocate for the Labour Party but actually pushes politicians from the left? If so, could they be useful enough to everyday people (I mean actually useful, like providing actual help) that they would join up and grow the left? As an outside (far outside) observer, I would guess not. How could they change that? Or maybe the most left in that organization could branch off and try to start something that tries to go in the direction just described. Right now if Momentum members threw a pound in the pot every month they could fund a lot of left media. See how that works?
Yes, there is an irony, or maybe more specifically a catch-22: In order to have a large effective left media, people have to be educated about politics and more specifically they need to have a solid basis for an analysis. And in order for people to be educated in that manner it greatly helps to have a thriving left media.
A thriving left media can be built out of a thriving radical movement, but we don’t have that. At the moment, all over the world, the left continues to be atomized and essentially refuses to organize itself and unite under one flag. There is a little movement in the right (correct) direction in some countries, but viewed optimistically, the most you could say is that it is nascent. If you listen to left media and left orgs, you can hear brief mentions of the necessity of the left to be an organized international force, but that is putting the cart before the horse because the majority of the left in most countries think they can stay in their own lanes and just get together for protests and specific events – and even worse, there is a conventional wisdom that permeates the left that assumes building a unified left under one flag (say a party or something like a better IWW) is not only not necessary, but is a bad idea. I have no problem with a diversified left, but one that isn’t as organized and unified as capitalists are worldwide can never hope to win, let alone put up a credible fight. When we are faced with actual extinction, not being organized and unified is not an option.
To tie up this non-comment comment, an organized unified left could easily fund left media. Not only that, but a media that is organized and unified worldwide could more easily share information, knowledge, resources, and would definitely help build the left and the movement we need.