Its not so much the device in this case that is unfit for the purpose (well - unless it is, as described above..

) - it is, that the minds that are interested in and forming around solving those problems are working on much better (reputation) and wider known projects - AND the devices they support cost anywhere from 10-30 bucks used already. So dont tell them why you bought a Fire TV instead.
I know that current "technophiles" see the world as app based solutions that will come to them if they ask around often enough - but really, we already are at the minimal knowledge and minimal cost stage - and they are in essence complaining about convenience.
I have a problem - and see the solution in this one ethernet port another device I bought already has. Let the internet work out the rest, I am waiting for my app - its already rooted, how hard could it be.
And thats not how this works.
First of - why should they be working on an app based solution? A functionality layer if you will - if they dont have control over the entire ecosystem and networking, I heard has something to do with security. Sometimes. And with devices that have to work longterm - quite unlike the little plastic box that currently sits under your TV. And that today is rooted but tomorrow might not be - because, well its not yours to decide. Entirely.
dd-wrt and openwrt are what you are looking for - but that was already mentioned by the person posting before me.
I'm just here to explain why the "asking for a service" mindset ultimately breaks, when it comes to open source movements. Especially when your demands get more and more specific. ("I have bought a...")
I can say all this, because I currently use ddwrt to service some of my needs and it works perfectly well, creating all kinds of synergies I actually actively use - many of which actually are real enablers for owners of Android based Kodi boxes.