Can someone set up his HTTP server to not serve index page or any other unless the user made requests to my self hosted ads?
Can this be accomplished by a PHP script that gets served when a user requests a page along with ads, checks if ads were requested and downloaded and then serves the real page with content?

I feel this is so viable and very hard for ad blockers to bypass unless they waste bandwidth by requesting ads anyway and just hiding them from user, so why are not a lot of websites doing this? Would these sort of scripts by punishable by google somehow?

I am not a webmaster myself and I use an adblocker, I am just worried from rising trend of ad block use that webmaster resort to this with no real bypass around it.