Huh? One example: everyone did sideload Pokemon Go in 2016 because its availability on Google Play was very limited for a very long time.
So why didn't Pokemon Go pull out of Google Play? Your only example is from 6 year and keep the 30% which Google takes? You only have one example from 6 years ago and people only sideloaded there only because it wasn't available on Google Play.
The one example you provided proves the opposite of what you wanted lol
"One man’s modus ponens is another man’s modus tollens"...
So all they need is 20 years to build up a fanbase in a product universe worth tens of billions of dollars and everyone will be clamoring to sideload their app as well.
But this does contradict your point that "nobody installs apps from outside of Google Play". And, if they're installing something like a loyalty app, they won't care very much whether that QR code leads to Google Play or to an apk. The process is really no different than running an .exe you downloaded on your computer.
that's not exactly true, though of course I don't have numbers.
maybe that is something you just don't see a lot, but that happens often?
Look up the Epic/Fortnite situation and the only conclusion from its development and Epic's decisions is that it almost never happens and unless your market is exclusively techies you'd be foolish to consider it viable as your sole release channel.
is that why Epic required you to sideload the game for the first couple of years of its life? because no one sideloads?
They tried to make it its main distribution channel to avoid having to pay Play Store fees. They ceased doing it because it was much harder to acquire customers via sideloading despite the product being motherhugging Fortnite than it was to pay the tax on every "micro" transaction.