Virtually all applications that an Android OS user has on their Smartphone, are installed from the Google Play Store. (It is for this reason that Huawei has been in bad shape when leaving Google's friend's yard).
However, as it is a much more open operating system than iOS, we can very easily install applications from outside. (It is also for this reason that, despite being 'hurt', Huawei remains very much alive in the smartphone market.)
In short, there are many applications 'coming from outside' that can be installed on the Android OS without any restrictions by Google. Something that the company ceased to find much joke, now starting to try to ban gradually.
That said, we know that Google's advanced protection program will only allow Android users to install applications from the Play Store (or other official stores -> Certified by Google). Thus prohibiting the possibility of installing third party applications from the Internet.
New measures by Google aim to improve the security and privacy of all Android users!
Therefore, privacy and security issues are once again brought up and are currently the main objective of Google.
After all, according to the company, an application from a website can be very tempting. But the person in question may not know the amount of Malware that that application can bring to your Smartphone.
Well, Google knows that these measures will not be the 'cure' against this problem. But even so, it could be a good way to significantly decrease the number of people who spend their lives installing applications that are not recommended, and then go 'cry' for support from the software giant.
That is, Google is preparing to activate the advanced protection program, making it impossible to disable.
In short, Androids smartphones alone already have an incredible security capability against the most varied types of Malware. However, it seems that Google with these new measures wants to reinforce this to the maximum and prevent that there are still cases of security breaches and breaches of users' private information through third-party applications.