Do you want ISPs or other intermediaries to be able to inject ads into static sites?
https://www.charlesproxy.com/documentation/proxying/ssl-prox...
Is there anything preventing page alteration on unencrypted connections? There's certainly an incentive to do so.
* ISPs and other intermediaries have the wrong incentives: reading and modifying plaintext traffic can be very profitable.
* Sites have the right incentives: they don't want to be messed with or snooped on.
On unencrypted connections, there's nothing preventing an intermediary from altering a page. Assume it happens.
On the other hand, a complain by all the customers of the service over the entire country who understand the issue could make a difference.