This problem is hardly specific to Android. In some ways, this is really just common sense.
If you're not paying for it, and it's not an open-source project, then you can safely assume that you're paying for it with access to your personal information. That's why Windows 10 was a free upgrade. That's why most of Google's services are free. It's the same story with Facebook and so many other things. Amazon's Alexa ranks pretty high on the list, too.
The point is, if this wasn't true, then we would have far fewer free apps on Google Play. And it's kind of silly to think that switching to another OS is going to grant you immunity to being tracked. There are precautions we can all take, but it's pretty much futile to completely avoid having data collected on you.
I use Android, but some of the things I do to mitigate this are:
I download as few apps as possible. I don't bother with free games. If a website suggests that I download their app, I decline the offer and use the web browser instead.
I use open source apps wherever possible. For instance, I use Firefox as my mobile web browser, and QKSMS as my messaging client.
I use the system default apps that come with the phone, if they don't suck. For instance, Samsung and Google both have their own apps for viewing photos and listening to music, but I avoid using the Google apps unless it's necessary.
If an app asks for permissions that don't seem necessary, I'll uninstall it and look for an alternative.