Everything was faster in C - it was compiled and BASIC was interpreted.

Better comparison would be between C and Turbo Pascal strings in DOS times. TP strings were limited to 255 characters but they were almost as fast as C strings, in some operations (like checking length) they were faster, and you had to work very hard to create a memory leak or security problem using them.

I've learnt Pascal before C and the whole mess with arrays/strings/pointers was shocking to me.