For my Gnomies, the Run-or-raise extension [0] is stellar. It does exactly what it says: you bind a key combo to a launcher command, and optionally define a windowname or wm_class query to check for the existence of the program before it's launched. If it's running it's raised, if it's not then it's run. It has options for the window behaviour after toggling, optionally minimising the programs etc.

I can't rate it highly enough. It helped me finally step away from my decade-long i3wm-adhd addition, where everything else failed.

[0]: https://github.com/CZ-NIC/run-or-raise