Control. Remember that Google isn't a product company. Their business is selling attention of the users who use their internet products. Devices and OSs are a

Control. Remember that Google isn't a product company. Their business is selling attention of the users who use their internet products. Devices and OSs are adjacent to their business so, they don't care which ones win, they just want to make sure no large player emerges in them. When you have near-monopoly power, you want the layers adjacent to you to be commodities. That's why they bought Android, put a lot of resources behind it, and open sourced it. It prevented Microsoft, Samsung, or anyone else from owning mobile OSs the way Microsoft had owned the desktop in the past generation.