If I understand correctly, it used to be considered a path to enlightenment / nirvana / liberation etc by itself, not just as a mere supplement. Way different from today's new age / feel good / get fit commercial yoga.
Yes, that's right. I was referring to the Western "Yoga" which is just stretches and breathing exercises.
Actual Yoga had several "limbs" or modalities you can follow and involve immersion. Your life becomes it. It's not like the gym where you forget about it between sessions but rather you aim to change (develop) your being.