WebRTC is what I really want from the video part of the software. For me, WebRTC is the best way for people to communicate with webcams on the internet. It is simple and widely used. The messenger for me might be a bit of a hassle to maintain because I just want to build the site and forget about it without needing to make sure that it is still working properly, as far as expired ssl certificates, etc. I really don't want to worry about the streaming server. I vote WebRTC for it's ease of use. I think that I said that right, but it is more of a notion.
The idea can be to disable all video and file uploads to just make it for photos, gifs, emojis and streaming webcams. No real server storage.
You will still have to worry about expired SSL certificates in order for the WebRTC to work. Webcam capture works ONLY over a HTTPS. Anyway what do you mean by "streaming webcams. No real server storage."? The original question was "can record video from desktop" - which is a bit different I believe.
You can uninstall the Videos module, disable all uploaders everywhere, but you will still need some custom module/software to be running in order to make streaming possible. So perhaps the messenger is the best option for your use case.