This is happening to me right now. I have run a site for 14 years that gets most of its traffic during the current two week stretch (it's related to NBA playoffs).
All of a sudden, Adsense revenue has gone to basically zero. $90 of earnings from Sunday has even disappeared.
There is no way to contact a real person at Google. You can just post in their dumb little forum and someone with no authority who doesn't even work there will reply to you with the same pointless info from their FAQ.
If things go the way they have been, it seems like roughly $2k in revenue that's been pretty consistent for the last decade is going to be basically zero this year and there's nothing I can do about it.
Thankfully, this is just a side project and I'll be fine, but its not hard to see how they could screw someone over who relied on it.
The key factor is the timing. During the primary week where this product generates income, Google completely screwed me over with no warning and no answers about what's going on. I am of course looking into alternatives, but that takes time, and 3 days from now it'll be too late.
You have no contract with Google though. You're literally siphoning on what is a really low-barrier, dare I say free service.
They didn't screw you over. You chose to use them. You didn't pay them, they're paying you.
If you don't like that arrangement, feel free to join a partner agency that can buy and sell ads for you on the ad exchange or go to a different ad network.
Then, if they do something you don't like, you actually have very real power to compel them to do something.
Not parent, but there are many examples of this; they’re often (but not always) unsympathetic cases due to the business model of the business which has been destroyed.