Google set Project Zero on finding exploits for the Fortnite installer and then engaged in a media campaign to promote how scary installing it was.

I would say in addition to the "scary stuff" warnings Google employs on devices, they went out of their way to harm any serious contender for outside distribution.

Epic also went on a significant campaign to be allowed to distribute through Play, but utilize their own payment provider, but Google's monopoly wouldn't budge:

Google's Play Store demands aren't about security, they're about the 30% taxation.