I don't know any GUI that beats tmux work portability.
Of course everything depends on exact nature of the work, but personally I would gladly leave text based interfaces behind, it's just that there's nothing better.
I don't want "a terminal", I want a command based interface combined with being able to use the same set of tools/commands on all the files I interact with.
Like, it gets taken for granted, but being able to literally grep my html file, my program source and my readme file, instead of having to open a separate gui program and using its bespoke seach menu feature, is really, really nice.
There are downsides of course, like the way we keep jamming everything into the square hole that is 1980s terminal emulators and character based displays, but frequently this is worth it.
9front does that without emulating a terminal. Grep, cc, awk, walk (no find and magical incantations with -print0 there), functions instead of aliases on rc, better lists () in rc, and so on. And you can launch these command inside your graphical editor such as sam or better, Acme. And even as a pipe to selections.
No Perl but there's rc, awk and aux/* helper tools which can do tons of stuff Perl does but without calling tons of CPAN modules. 9front ships an IRC client made with rc, awk and aux/trampoline to connect (and tlsclient for TLS connections).
I mean, the point here is the standardized input/output system that leta everyone build programs without knowing each other that more or less interoperate.
That's Unix philosophy and 9front perfected it to the extreme. The bundled IRC client it's a shell script with two network helpers, one for plain conns and other one for TLS.
Thankfully Xerox PARC has an answer for that across Smalltalk, Interlisp-D, XDE, and Cedar, and copied to certain extent in modern programming languages, REPL environments and notebooks.
Augmented nowadays with agent environments and tools in IDEs, which can even be voice controlled.
9front/plan9 leaves tmux and the like as toys. The moment you can use system tools, 9p and files on everything (even the text of the editor itself) you wont be back to these unusable teletype emulators, be XTerm clones or terminal multiplexors.
Of course everything depends on exact nature of the work, but personally I would gladly leave text based interfaces behind, it's just that there's nothing better.