I challenge the idea that private enterprise could solve the scaling component better than a government could. We've reached this comedy of ads and surveillance capitalism because private strategies are flailing.
Or maybe there just won't be any cat videos, because the state has decreed them unnecessary or even harmful? How about political messages, is the state going to allow those to be posted on its platform? There are bound to be a few that go against state policy...
You could argue that the same is true for broadcast TV, and I would 100% agree. The state has no business running or even funding public television.
The problem here is that we're already only having this debate because people refuse to pay, even when what they're paying with is functionally intangible (i.e. their letting an ad play on their PC for 30 seconds.
So any model which relies on people physically paying real actual money* is doomed to fail to begin with because you're not solving the issue.
There's also an issue with the payment model. Creating an account, sharing a bunch of personal info, and subscribing on a recurring basis is entirely different from the USPS model where I walk into the post office and pay a one time fee in cash to get my letter where it needs to go. I suppose an analogous service might charge $/gb/mo paid up front without requiring an account. Like catbox.moe except paid.
Also remember that legitimate creators keep being demonetised for no reason because AI moderation has a brainfart and no human is in charge.
And then there's the clusterfuck around malicious copyright strikes made for bad faith reasons by non-owners.
With public infrastructure there's at least some nominal possibility of democratic accountability - not so much in the US, large parts of which are pathologically delusional about public infrastructure as a concept, but it should be an option in countries with saner and more reality-based policies.