Most applications do ship in a single container. whether it's a single binary inside, or a bunch of python or js files or shell scripts is a separate issue. If there is a dockerfile then you know how to build the container. a single binary is easier to build the container for yourself, assuming you also know the binary dependencies of that single binary. Like maybe ffmpeg or yt-dl cli on the path?
Applications that ship as a list of containers are a completely different problem. Those applications are either a victim of their own success, or have developers that come from a particular background.