Apple is a company I could see making it a priority, because they tout privacy as a major selling point of iOS. There are entire ad campaigns about it. It's not perfect, but they've done a lot in the name of privacy, even when it costs them money (e.g. all the bad press that came out about iOS when they added a notification for when apps were accessing your clipboard...and it turned out a shit ton of apps were just scraping your clipboard all day).

Google, though...yeah. Android has some privacy control, but in reality they're mainly following Apple's lead so as not to lose customers who care about privacy. I don't think they actually give a damn about consumer data, as long as they get their share of tracking done. There are more privacy-oriented ROMs out there, but the average consumer is never going to use anything other than the version of Android that came with their phone.

It would be nice if there was some third-party entity that performed privacy analysis of popular applications and provided a score on some sort of privacy index that could be featured on that app's storefront. It's a shame that we are just left to assume how much of our data is probably being harvested and there's nothing to be done about it.