"allowing their main competitor to keep subsidizing development of their iOS operating system."
I do not think this is true. Apple simple spend money to develop iOS so it can sell iPhone. You could not sell cars without engines and you cannot sell mobile devices without operating system. The entire ad money subsidising X phenomenon exists because Google does it, very successfully. I absolutely dislike the concept of surveillance capitalism and I do not want to participate in this. Mobile phone vendors should develop their own OS and price their products accordingly instead of forcing me to consider only iPhone/iOS if I do not want to install some hackware or adware as the OS of my device. I want to pay for the goods I use and it is not ok to give something for "free" when free means that my entire digital life is sold for the higher bidder.
If you order Google to abandon the project, you're effectively ordering to stop them from investing into the operating system while allowing their main competitor to keep subsidizing development of their iOS operating system.