I think the interstate highway system might be an even better example. An absolutely essential part of business infrastructure and personal lifestyles, built and maintained largely at government expense, yet hardly anyone is asking for it to be torn down or privatized. Not even the parts that have tolls. (Yes, there are a few who suggest this, but even by right-wing/libertarian standards they're considered a bit crazy.) Just as anyone with a driver's license can drive on an interstate, anyone should be able to participate in the internet. It's not that much of a stretch from there to saying they should be able to participate fully, which means being able to host sites or apps. It doesn't have be be completely free of cost (see: tolls) but should be freely available and run for the public good. That's no crazier than the interstates.
Either you need industry charges to cover that cost to government, or a mandate that they can't ignore expensive customers.
Like, corporate taxes?
There are lots of options each with their own trade offs.
Apps are probably not the right target for that, but Amazon might well be — it has expanded to the point it needs its own delivery network because government owned post isn't enough in certain countries.
It would be a massive pain to do this well, certainly more than would fit into a comment box like this. And not just because it's a multinational, and different governments will have different opinions about the process of nationalisation.
I'd bet that <10% of what you pay for an EC2 instance is hardware acquisition and labor and electricity. The other 90 is in support of the never ending zero-sum game that is fighting over market share.
Compare it to municipal internet, in which you usually pay less to get more because you can fire the marketing department.