I am not defending a Garib Rath's CC. I dislike the concept of Garib Rath in general. But speaking of Chair Car, there existed before Corona, the Yuva Express from Delhi - Howrah which was technically the fastest on the route at 17 hours and it had many Chair Car as composition.
If we go way before, then 12301 NDLS-HWH Rajdhani when introduced, had a sitting rake and AC First Class rake only. So, yes IR has implemented with the sitting concept for long distance trains as well.