Yes - advertising is very profitable. Increasing the cost would lead to a short term reduction in spend by advertisers, which would squeeze the adtech industry. They’d respond with improvements to their specs which reduce bandwidth and return levels closer to normal. Totally fixable problem with the correct incentives.

Interesting note, the privacy sandbox apis that google (was) is pushing were extremely bad for bandwidth to the point that in early tests our servers often did not respond in time to successfully bid in an auction. This occurred in many steps different steps of the auction (ssps as well). Google of course kind of moved away from this set up before fixes were implemented. (If the time between a user loading a page and the result of a programmatic auction is too long, ads may not be served)

The biggest negative externality of advertising is the fact that it drives mass overconsumption.

Advertising doesn't inherently imply wastefulness or even being spyware or a malware & scam vector.

If all the negative externalities were properly priced in, a lot of bottom-feeding crap at all layers of the stack will die off, but advertising itself will remain and would actually become better as a result for all parties involved.