Was it just created to make an easier alternative to writing 4/4?
It's the other way round. The "C" is a leftover from the earlier mensural notation system, where each note duration was be divided into either two or three parts without the use of "dotted notes" as at present.
Divisions into three parts were called "perfect" (probably because the catholic church invented most of the terminology, and the Holy Trinity was perfect) and two parts were called "imperfect".
The symbols used in mensural time signatures were a complete circle for "perfect" subdivision and a broken circle for "imperfect" - which mutated into the letter C.
The complete system of mensural symbols added a dot in the center of the complete or broken circle, and/or a vertical line through it. The broken circle with a vertical line mutated into the modern "cut time" symbol.
The complete circle symbol became obsolete, because modern rhythmic notation doesn't allow for the idea that a whole note might sometimes contain three "half notes" not two, except by writing a dotted whole note, or using triplets.