A physical therapist costs significantly more, which is why a lot of chiropractors in rural areas with a lot of manual labor are well looked upon. They are mostly just practicing physical therapy without a medical license which could get them in trouble if it wasn't considered chiropractic work. The pure quackery doesn't get them as far because most of their customers are too poor to regularly spend on woowoo crap.

In my area someone's insurance might cover the first 3-4 sessions of physical therapy, but nothing after that despite them needing it for longer. So the physical therapist will at the end of insurance billing send them down the road to do the exact same thing at the chiropractor for significantly cheaper.

In places without a lot of manual labor they are probably mostly just the quackery. Their clients are lots of hypochondriacs and office workers who really just need to get more exercise but are willing to find anyone who says they can make them better without significant effort. Im sure the massages and stretching does feel good though atleast, but im sure a massage parlor would set out some crystals and do a massage for cheaper.