Impossible to create
I'm not so certain. I used to buy a broadsheet newspaper, which was full of ads. Now I pay a few hundred a year, and get the same newspaper online, with no ads at all.
So, the precursor to online media has already gone through this paradigm shift.
It's not, it just requires creativity. One example I can think of is limiting connectivity by distance between nodes. Something like Meshtastic seems unlikely to ever be commercialized in the same way that the Internet has been. Sure, you would lose some useful applications of the Internet, but you would gain other things.
Also for better or for worse the ad-centric model to some extent has allowed more people to access information.
Gating everything behind paid (but with no ads) likely would hurt a significant amount of lower income users.