I always get a little irritated when this comes up and people reply with, if you want to stretch, don’t do yoga, just stretch. Yoga isn’t stretching. It’s exercise. If you think it isn’t, then take a class

No one in my classes is praying to Hindu gods, we are trying to work out and build our core strength and use our flexibility. There is absolutely nothing wrong with becoming aware of our bodies. Some people like cross fit type exercise where you fling yourself crazy around and hope you don’t hurt yourself while you do a hundred dead lifts. Others of us like to become strong by a routine of moves using all our core strength, all our arm and leg muscles or even being able to lift our bodies off the ground onto our hands while perched on our elbows- slowly, balanced, and after much, much training

The only prayer I’m saying is God, help me hold it all together!
Now as far as New Age in general, yes I would agree with the OP- I get very concerned with things that claim to have magical powers. But there is a line for me between natural healing (such as with essential oils) versus bogus healing (rocks and crystals). God created plants with certain properties and we can learn to use them, nothing wrong with that imo.