Google attempting to claim any percentage of revenue from an external transaction will never happen. I believe the current situation with the App Store is that Apple has been barred by US courts from attempting to charge a fee similar to this; though they still do in the EU. USG antitrust, especially in the current admin, hates Google, far more than Apple; this structure will never survive being challenged.

Charging a reasonable fee for the installation of an app can be, IMO, a fair and reasonably cost-correlative way for app store providers to be compensated for what few services they do provide application developers. That's within an order of magnitude of how much bandwidth would cost, if they were paying market cloud rates, and certainly there are other services rendered, like search indexing.

I would emphasize to the people at Google, however, that your customers bought the phone, which came with the operating system, and thus ethically the core technology your application developers depend on has already been paid for. In Google's case, this happens through Samsung/etc's Android licensing; a relationship which landed them on the wrong side of antitrust lawsuits in the US quicker than Apple's racket did. They dip further by charging developers a direct fee to publish on their stores ($100/year for Apple, $25/one time for Google). Attempting to triple-dip by "reflecting the value provided by Android and Play and support our continued investments across Android and Play" convinces exactly no one of your benign intent; not your investors, nor the US Government, nor consumers, nor developers. The only person who may be convinced that any of this makes any sense is some nameless VP somewhere in some nameless org at your mothership, who can pat themselves on the back and say "at least its legal's problem now". Its possible no one at all in this business unit remembers what the words "produce value" even mean, let alone have the remote understanding of what it takes to do so. Exactly everyone who has ever interacted with it know this; your CEO certainly knows this, given how much investment he's made into AI and not into the Play Store. Continuing to cause so many global legal problems, for such an unpromising, growth-stunted business unit, is not generally a good recipe for keeping your job or saving your people from layoffs.