As per the surveys & Reports, available online, the need of Cardiologist are going to increase by the end of this decade. As there is demand of Cardiologist, providing lesser salary isn't at all logical. The saturation of doctors in India will not happen this fast, because at present India have quite a huge need of medical professional of all the fields be it General Medicine to Psychiatric Medicine. So if you wish to go for Cardiology, just go for it, this kind of rumors are all over, but the data is speaking otherwise.

For more information regarding the career in Cardiology you can consider the link below:

https://www.careers360.com/courses/cardiology-and-thoracic-science-course

I hope this helps. Wish you a great day!