It's not uncommon for Android malware to exploit system vulnerabilities to break out of the sandbox. - Agent Smith abused an installation vulnerability in orde

It's not uncommon for Android malware to exploit system vulnerabilities to break out of the sandbox. - Agent Smith abused an installation vulnerability in order to inject malicious code into other installed APKs on the device. (https://research.checkpoint.com/2019/agent-smith-a-new-species-of-mobile-malware/ https://research.checkpoint.com/2019/agent-smith-a-new-speci...) - HummingBad used multiple root exploits to auto-root 10 million devices. (https://arstechnica.com/information-technology/2016/07/virulent-auto-rooting-malware-takes-control-of-10-million-android-devices/ https://arstechnica.com/information-technology/2016/07/virul...) - xHelper similarly buried itself deep in the system partition in order to survive device resets, and went so far as rewriting libc.so to prevent you from mounting the system partition to remove it. (https://arstechnica.com/information-technology/2020/04/solved-how-android-backdoor-called-xhelper-survives-factory-resets/ https://arstechnica.com/information-technology/2020/04/solve...) You are also underestimating the amount of damage malware can cause even within the sandbox. - The CryCryptor ransomware abuses file access APIs to encrypt photos and videos on external storage and hold them hostage. (https://threatpost.com/emerging-ransomware-photos-videos-android/156893/ https://threatpost.com/emerging-ransomware-photos-videos-and...) - The DEFENSOR ID banking trojan abuses accessibility APIs to steal login credentials, text messages, and 2FA codes. (https://www.welivesecurity.com/2020/05/22/insidious-android-malware-gives-up-all-malicious-features-but-one-gain-stealth/0/ https://www.welivesecurity.com/2020/05/22/insidious-android-...) Even the majority of the adware you describe abuses system APIs to hide their own icons and draw their own ads on top of other apps. (Why Android even has an API that allows this, I have no idea...) (https://news.sophos.com/en-us/2019/10/08/icon-hiding-android-adware-returns-to-the-play-market/ https://news.sophos.com/en-us/2019/10/08/icon-hiding-android...) When it comes to malware, sandboxing is far from the panacea that some people seem to believe.