So something like abduco (https://www.brain-dump.org/projects/abduco/) should do the job too? I think GP's comment was more concerened with the terminal multiplexing, not the ability to detach a session.
abduco claims to be a tmux alternative, which there are probably a few - I don't think any of these points being made are attempting to claim tmux is the only tool with these features, only that the features are very useful - tmux just happens to be one of the most popular tools in this category of tools
