So the current way kde appliactions handle Menubars/Hamburger menus is sub-optimal. I propose that additionally to the per-application settings there should be a setting in systemsettings that sets a default, (show menubar / use hamburger menu) that any application gets its default value from, but can still override.
It's not a bad idea, but there are more than just two options for how to show menus. The full set of options is: - in-window - hamburger menu on toolbar showing curated menu structure - hamburger menu on titlebar showing full menu structure - global menu widget in a panel showing full menu structure And an additional complication is that each option only supports certain apps. For example if you chose the "in-window" option, you might be frustrated that non-KDE apps didn't change accordingly. I think this has the potential to become a "broken promise" global option; see https://community.kde.org/Get_Involved/Design/Frequently_Discussed_Topics#%22Broken_promise%22_global_options. So for now I don't think we'll be considering it, sorry!
Ah OK, I hadn't quite considered the complexity of such an option.
Yeah it's a bit unfortunate. I sympathize as I would like such an option as well, and have proposed it myself in the past. But the devil's in the details, and making it work in a way that doesn't mislead people or require buy-in from 3rd-party apps (which never happens; they don't care) would be extremely tricky.