Sure, and there's places other than amazon to sell.

That doesn't matter when the Play store, or Amazon, controls the majority of all sales. How much money are people making on APKpure? Is it enough to support a dozen software engineer salaries?

Didn't think so, no. Getting booted off of the Play store does not mean your app is impossible to share, but it decimates the size of your audience - worse, even. Will even one in one hundred be left?

Indeed there are, but most people are wisely taught to avoid them as there is more risk of installing an app that may have nefarious (hidden) behaviors.

So practically speaking, distributing your app outside of Play store is going to severely limit your reach.

I'd rather build a web app and try to get people to create a "desktop" shortcut.

I think a PWA (progressive web app), that people get directly through your website, is a more viable alternative.

As long as you don't need some native-only functionality of course.

What fraction of a percent is the market share in app installs?