i spent most of my working career in C, and as advised by my early mentors, over the decades, i have build, and have continued to hone my own little collection of useful functions.
i have learned interpreted languages, bash scripts, also postscript and forth along the way, various others...
in the end what remains best is C code, and my own little legacy collection of solutions to the problems i have encountered.
to answer your heads as best as i can:
archaic - C is not - underneath every "other" language you will almost always find C source and a C compiler.
text based - think AJAX if you want instant and easy access to gooey bling stuff. these days almost everything that can do GUI can also do an RPC text based interface of some form or another, and if you don't want the fuss off rolling your own interface, there are plenty of stock C libs out there will do this for you.
not a hotshot - you know C, you are not only hot, you are a rare breed, and an essential part of the future - as i said above, C lies beneath just about everything out there, and large parts of the Original Framework is now inscrutable to the script kids, despite their whole world would collapse, if there were no-one left to maintain it.
update your coding skills - in short please stick with C as much as you can, and think about building bridges - in my opinion your time would be best spent studying the C and text interfaces exported by other languages, and working out for yourself how best to leverage their abilities from within C - as opposed to jumping ships.
help out - get yourself a git account, share your work, if you can.
in all of these except the last i speak from 30 years experience, and in regard to the last - i'm working on it - most of my stuff is still bound in commercial licence, however i continue to hope this will change, eventually, and i continue to prepare for that day.