My perception is also that malware ends up in the Google Play Store with much higher frequency than the App Store. Just do a news search for "Google Play Store malware" and "App Store malware" and compare.
Also, one can sideload apps, if you have a Mac, onto iOS. Obviously, that's not anywhere as integrated but maybe that's a good thing. Heck, maybe Apple even added that so people in China could sideload VPNs. Maybe iOS VPNs are good enough (no root, no TOR?)?