I used to feel the same way until I actually watched a Formula E race.
The racing is incredibly close at times (I think last race had a 3 wide finish for the podium), and features like Fan boost make for a really engaging overall experience
When I open an .apk file from a new application for the first time, I get a popup that asks me if I want to allow installations from unknown sources for this app, with a button that directly takes me to the setting to toggle this, and then immediately allows me to install the application.
Side loading on android is laughably easy, probably easier than installing a program on a Windows device. If we can consider the installers that Windows users need to use to get something as simple as Chrome installed easy to use, downloading an .apk file and opening it and pressing install should seem trivial by comparison.