That's not just proprietary, it's surveillance capitalism. "Subscribe for early access and monthly progress updates." You should be embarrassed for posting that kind of filth on a thread about asciinema, which is a free-software program that works offline and has strict privacy protections.
Also, codemic.io seems to be oriented toward full-motion video, so aside from the authoritarianism issues, it's not even related.
I think you're misunderstanding what it does. It's not sending your data to the cloud. It just lets you record a session when you press record. Also it's opensource too.
Hmm, maybe I jumped to the wrong conclusion. Is it like a delayed open-source release thing, like "sponsors get access to new releases before the open-source release"? I'm trying to understand how "subscribe for early access" coexists with "it's opensource".