I'm a neurosurgeon whose specialties are pain and spine surgery. In fact, I have 2 cervical spine operations scheduled tomorrow.
I feel like I've commented on this issue a number of times between here and the old site.
Yes, chiropractic is pseudoscience. It is also a placebo. Sometimes the placebo works. Sometimes it results in tremendous damage.
I have personally operated on (at least) 2 patients with vertebral artery dissections secondary to neck manipulation. They required a posterior fossa decompression, which is removing the bottom back of your skull to allow the ischemic cerebellum to swell and not kill you. One patient died, the other was left in a nursing home. This is a rare incident, compared to the likely millions of necks cracked it would take to result in one dissection. Maybe these people already had arterial irregularities; hard to say as they were never investigated because they were so young.
Most people who go to chiropractors get their backs cracked; a lot feel better, and a lot swear by it. Patients often come to surgeons looking for surgical answers to their back pain, when in fact there are none. Back pain is rarely a surgical problem, and when it is, you usually have other problems as well. I tell patients they need to lose weight, stop smoking, see a physical therapist. Some patients do, many do not. Chiropractic is an easy, passive "solution". Some patients do not want to put in work and effort towards improving their health, hence why they demand surgery and will continue to "shop around" until they find a willing (or more than likely, greedy) surgeon.
Back pain is multifactorial. As I've already mentioned, anatomy is only a small contribution. We know that pain is composed of sensation, cognitive, and affective components, meaning that 2/3 of all pain is in your head and based on your perceptions. We have loads of evidence that depressed people do worse with surgery or spinal cord stimulation for pain, smokers do worse, obese people do worse (maybe, still contentious).
So why does it work for some people? Probably because they want it to work. Feeling and hearing a cracking sound is cathartic and is a physical sign that "something" has happened. Although that something is actually nothing, it remains a powerful motivator.
Do we recommend chiropractic care? Never for the neck. Maybe for the back, depending on what conservative measures you've already tried and/or failed, and depending on how motivated (or not) you are in taking control of your own health.