> Google shows countless scary warning dialogs to users who even think about installing a third party store. Any competitor trying to run an alternative store needs to somehow educate potential consumers on the process of enabling "unknown sources", and convincing them that doing so won't actually kill you (translates directly into higher business expenses, and is probably an impossible obstacle to overcome to reach the majority of consumers)

It is a single setting/message about allowing you to install apps from unknown sources that you can grant for that specific app. You can enable/disable anytime.

> Google regularly monitors apps installed outside of the Play store with their "Play Protect" thing, which is an opt-in virus scanner, except not really. When you install an APK, they ask you for permission to enable Play Protect. If you decline, they'll just keep asking you again and again until you accept either by accident, or do it so they stop annoying you. Through Play Protect, Google is able to arbitrarily block any app they consider to be "potentially harmful". Consider that they regularly ban apps by accident on the Play Store using their broken AI, and that those registered developers struggle to get those erroneous bans reversed. I'd imagine getting a ban from Play Protect reversed is nearly impossible.

I have multiple apps installed from F-Droid and I have never got a single message from Play Protect warning me of anything.

> Google has a full time hit squad of penetration testers called "Project Zero" which goes around checking competitors for vulnerabilities so they can make big scary press releases about how unsafe the competition is (even though Google Play itself is riddled with malware).

I've never seen Project Zero act unethical or unprofessional to gain a market advantage.

> Yes, Android is open source. The operating system on your Android phone is not open source.

Depending on the phone you get. Many people specifically pick manufacturers that are more friendly to open source.