I don't know how much it should be worth, but at least there's a PR effect and it's also a message towards the dev community.
I see it the same way ridiculously low penalty for massive data breaches taught us how much privacy is actually valued.
For security researchers it's apparently obvious, but from the outside it's another nail in the coffin of how we want to think about user data (especially creators, many being at the front line of abuse already). As you point out Google here is only the messenger, but we'll still remember the face that delivered the bitter pill for better and worse.
How many young computer enthusiasts / aspiring security researchers are motivated to learn more because they see, what to them are, massive payouts.
You or I might not get out of bed for the hourly rate that translates to, fine by me - I have a job that pays the figure I negotiated.
Bug bounty programs pay the market clearing rate, always. One bug, two market participants, one price.