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.
We all know that sideloading is a well-established method used by millions of people to gain access to software that is not available on the dominant stores.
I didn't think branding them as developers would change anything.
Do we? Which common app is exclusively distributed though a standalone install and used by millions? I can't think of a single example which would validate that.