Sadly. It is still in beta though, so it’s still possible for a mobile version in the future. There’s a few discussions on the github asking about mobile support (no responses).
At the moment, our team does not have the time or resources to develop Android or iOS versions of Zen Browser. Additionally, we believe that Zen’s unique features, particularly its design around vertical tabs, do not translate well to the mobile form factor. As such, we do not currently have plans to develop a mobile version of Zen Browser.
Sadly. It is still in beta though, so it’s still possible for a mobile version in the future. There’s a few discussions on the github asking about mobile support (no responses).
Source
That’s exactly what I was thinking, there’s nothing in Zen that would add any value to Firefox on mobile.