Not sure what they’re referring to, but there are a number of warnings when you install an APK and you have to enable a setting to allow you to install an APK. It’s not challenging or restrictive, but a user who is unfamiliar might be discouraged from installing an app this way after seeing the warnings.
This is the integrated search on the home screen of my android (pixel). For a lot of mobile phone users, it’s the fastest way to search something. I can just Google search directly from the home screen instead of opening up a browser.