Your example is dead wrong. I run Gnome and my language shortcut is CapsLock. I used the Tweaks configuration software which is part of Gnome (it is the one you are supposed to use for more invasive configuration).
I do find Gnome plenty configurable. You just need to go in order of Settings -> Tweaks -> their weird registry -> custom extensions. I would agree this is convoluted, but I do not mind it (as a power user it took me 5 minutes to google how to do it, while it probably makes sense to have only the first state (Settings) visible by default).
The examples from the OP are configurable from Tweaks which is a GUI. No hacks, command line use, or third-party installs. In particular, the equivalent to the screen shot you showed is available from Gnome's Tweak tool.
You picked the 4th stage but conveniently skipped all 3 tools that precede it. The Tweaks tool is a GUI that is a part of Gnome and it deals with the examples that OP raised.
This is a rather childish way to respond to my comment... What is the point of being antagonizing like this? How do you see the conversation progressing or what point are you trying to make?
For context, I have used Linux and other Unixes for 14ish years, spanning the spectrum from embedded devices to supercomputers, with (or without) a variety of graphical shells.
I do find Gnome plenty configurable. You just need to go in order of Settings -> Tweaks -> their weird registry -> custom extensions. I would agree this is convoluted, but I do not mind it (as a power user it took me 5 minutes to google how to do it, while it probably makes sense to have only the first state (Settings) visible by default).