Those who can afford it could pay their own hosting fees, and donations, governments, and philanthropic foundations could subsidize the cost of hosting for those who can't.
Most businesses could of course pay for their own hosting, and even now don't operate on "free" (ad-supported) hosting services.
So, yeah, I'm not really worried about the survival of the internet if unsolicited ads were banned. There's already a glut of content being created every day, and that's unlikely to be significantly reduced.
The Internet isn't entirely run by volunteers with a hosting budget. Not by a long stretch.
Microsoft who lets people use the github cdn for free if they're not obnoxious about it.
and my mail server on linode which I'm paying for anyway.
Web hosting is just not that expensive unless your doing stuff like video streaming.
I’d pay for a non-tracking YouTube, email, news, and a small fee to access my banking online.
Also we pay ISPs who pay carriers who pay for peering with popular networks.
With federated platforms like Mastodon, PeerTube, PixelFed, you technically can network with 3 billion people, despite the lack of the central server.
Ads and heavy websites are slow and expensive to browse for half of human population due to poor connectivity.
That's entertainment or otherwise nonessential, no?
Some of the best parts of the internet are already free despite the option to monetize them with ads (e.g. wikipedia), if ads weren't an option, I think you would see many more spaces like that popping up.
It's cheap enough to run a server that people frequently do so without expecting compensation. Not everything needs to be paid.
Open street map and wikipedia runs of of donations/free labor so I don't think poor people would be kicked of those. Google would presumably come with your internet subscription, so that would be factored in for most libraries where the poor would access the internet.