Not necessarily. If licenses are cheap enough, and customization of the O/S to specific hardware is easy enough, the cost could be absorbed as part of production. The phone OEMs get nothing from advertisers. All that revenue goes to the social media and search engine giants, with a trickle to website owners. The main drivers of Android use by OEMs are (a) that it's free, and (b) that it's based on Linux, so getting developers to customize it is relatively easy.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows. -- 6079 Smith W.