I love how ghostty does windows/tabs/splits, but ultimately, I don't find myself using them. I find that I only have so much muscle memory in my hands, and I need to stick with one solution that works everywhere. A multiplexer let's me do this on my own machine, or if I'm SSH'd in elsewhere. Personally I use Zellij, because tmux feels like learning another vim. But I do use tmux when using tmate, because it's the simplest way I've found to share terminals.
Anyway, I'm very happy to see someone with Michell's talent entering this space. We can use more options with sane defaults and great performance.
The biggest strength to Tmux that a lot of the alternatives lack is you could make a shell script to setup your tmux instance(s) exactly as you would want, so by the time you load into it, its got all the tabs, split terminals, etc where you want them.