Beyond that it would devolve into a scenario where entities would begin trying to game whatever system is created to get a cut of the pie.
Forced support is not the answer.
For a tax assessment this would be based on wealth (e.g., property tax) and/or income. For an ISP-based assessment, the allocation might be more challenging, but a differentiation between business and residential usage (with a higher assessment for businesses, again on a progressive scale), and differentiated rates probably on a neighbourhood / metro region basis (so that a household on the Upper West Side and one in Julesburg, CO, would pay widely differing rates), is what I have in mind.
Rationale is that the wealthy have already benefitted mightily from such access, and the poor should not be denied access to media: news, entertainment, books, music, video, whatever.
You say "forced". I say enlighted common weal.
The poor are not denied access this currently. Everything in your argument hinges on the claim that government funded and directed media will be superior to the status quo. Why?