Android's openness doesn't come without a price, and one of the most cited costs is security. Unlike Apple's walled garden, Google has a hard time completely disallowing the installation of apps from third-party sources via APKs. The Android maker could only encourage developers and users to patronize the Google Play Store, but the final decision is ultimately in users' hands.

Link: Xiaomi MIUI Pure Mode can optionally block sideloading Android apps
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