I’ve actually started streaming stuff over my network to my Amazon Firestick which is different branding to your Roku but it’s the same principle.
My router has a USB port and I played around a couple of months ago with a USB stick and some files. Like many routers mine has the capability of sharing the contents of USB devices over the network. What I discovered was if I plug a USB stick into the router I can access the files from any device connected wirelessly or otherwise to the network.
There are options on this router to restrict access to specific devices but I want any connected device to have access and currently I’m not worried about restricting this as my device currently only contains media files.
Having setup the USB device, I installed VLC Media Player on the Firestick and on my Samsung tablet and I can now watch content of my large TV via the Firestick, my tablet, or any other device I choose. One big advantage of this setup is because it’s connected to the router it’s always available, even when the PC is turned off, and TBH even though I’ve only been doing this for only a few months now it has changed the way I watch stuff so much that I’d never go back.
The Firestick is plugged into my surround sound amplifier so I automatically get the full multi-channel audio whether it’s from stuff stored on the USB device, or content broadcast by streaming services.
Having played for a while with the USB stick I’ve now plugged in a 2TB external SSD which is working brilliantly. It’s very compact (about the size of a credit card), is powered from the USB port (so there’s no bulky power supply required), and has the capacity I need for a large amount of content.
You can use this setup for any files though, not just video, so you could also stream music, or even access data files by this method if you choose.
Anyway, if your router supports this capability you could test it out with a USB stick and see what you think. I’ve found it to be extremely convenient though.