Tmux control mode is one of the keys reasons I can't leave Mac. I also feel it's unbelievable that iTerm 2 is still the only terminal that supports this feature.
For anyone who is asking why this feature is good: it's really not that easy to see the benefits from the documentation, blog or even videos, until you personally try it. At least that's the case for me.
I worked on a pull request to implement it in Terminator a long time ago, but eventually gave up. Control mode was contributed to tmux by the author of iTerm2, and if you explore the iTerm2 codebase you can definitely see that they're very tied together in terms of implementation choices and general design. It's not that simple.
In order to have two-way synchronization, your terminal needs to not only have an architecture where you can add a background thread that can control the "main" terminal interface, but also be flexible enough to properly size all windows and panes, and match font sizing. If your terminal supports different font sizes for every pane/split, those have to be turned off in tmux mode. There's all kinds of corner cases.
For anyone who is asking why this feature is good: it's really not that easy to see the benefits from the documentation, blog or even videos, until you personally try it. At least that's the case for me.