Android is Linux-based, but Google still takes a lot of your data, like Microsoft with Windows. There are AOSP (Android Open Source Project) systems like PostmarketOS and LineageOS, designed to be fully de-Googled and therefore actually private, and there are also pure Linux phones, such as PinePhone and Librem, which use the standard Linux kernel but on ARM hardware, but these are mostly unsupported, and have few apps. Android is much, much freer than iOS; however, when it comes from Google or Samsung, it's nowhere near perfect.