Other than that I wouldn't mind some graphical features, such as being able to display thumbnails of images for example.
As many keyboards and computer terminals once directly generated ASCII code, the choice of control-C overlapped with the ASCII end-of-text character. This character has a numerical value of three, as "C" is the third letter of the alphabet. It was chosen to cause an interrupt as it is otherwise unlikely to be part of a program's interactive interface. Many other control codes, such as control-D for the end-of-transmission character, do not generate signals and are occasionally used to control a program.
Also see https://en.wikipedia.org/wiki/C0_and_C1_control_codes#STX
man ascii
H is 0x48, backspace is 0x08. ^H is the same as backspace.
I is 0x49, tab is 0x09, ^I is the tab sequence.
Now you know why Windows \r in text file show up as ^M in vi and Emacs.
^D is ASCII 0x04, "EOT (end of transmission)". That's why you use that to end input.
^C is ASCII 0x03, whose name is "ETX (end of text)". That seems a reasonable choice.
(I have done this in KDE's Konsole, so I can paste from a web form I must often use, which somehow blocks the standard Unix/Linux selecting-to-copy, middle-click-to-paste method.)
(…well that, and being able to use your thumb for performing the keyboard shortcut instead of having to use your pinky finger).
Linux isn't lacking it. It just has already decided on a specific shortcut. Do you also consider the absence of Ctrl-C to paste in Safari (in favour of Cmd-C) a lack?
At least on Linux terminal emulators you could always remap it (at your own peril, be careful about setting up another shortcut for the actual interrupt). Pre-Windows 10, OTOH...