You literally have to install a special tool to configure the look and feel. Did you miss the whole thing about how gnome devs don't want user themes to be supported? Or how they are forcing csd and dropping menus and config left and right? I'm guessing you weren't a gnome 2 user because it's night and day.
Trying to explain to a non-technical user that GNOME doesn't let them reconfigure something because the GNOME developers think they're an idiot who will be confused by configurability is a nightmare. I ended up telling my dad to install XFCE and he's not looked back since.
The problem isn't that GNOME devs are trying to make user friendly software for non-technical users; that intent is commendable. The problem is the GNOME devs have incredibly insulting opinions about the skills and intelligence of non-technical users.
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.
Gnome 3 has been out for 9 years now, which is longer than the time between the releases of Gnome 2 and 3. I don't think there is a lot of config churn. (It may have been worse in the early days of Gnome 3.)