This is fair, but I've found that I want to watch my content on a television instead of my computer monitor, since I already have everything set up. Unfortunately, it seems that there aren't many good options for just playing files on the network natively using Android TV alone.

It seems that a lot of people reach for Plex or similar in this situation, but setting up Plex requires a separate computer to serve the files. If all you want to do is play videos on your local network, then Kodi might be a suitable option, since it can run directly on hardware like smart TVs without the need to set up a separate computer.