In my experience, kratom is an addictive opiate, and requires a great deal of personal will and discipline to maintain a sustainable healthy relationship with it. It is much much easier than one might assume to fall into dependency, with increasingly dire circumstances, especially if one has a personal disposition conducive to addiction (*raises hand*).
I say this as someone who is currently neck deep in kratom dependency, so of course my opinion might be biased. I also may have lower-than-average personal will and discipline, considering I once struggled with opiate and heroin addiction for years in my past.
So here's my anecdotal evidence: My girlfriend developed an opiate addiction a few years ago, while serving as a caretaker for her terminal mother (she was in charge of all the pills), and she used kratom as a stepping stone to get off of opiates. It worked wonderfully, except that now we're both pretty heavily addicted to kratom. I had been free of all opiates for years when this transpired, with very minimal experience with kratom, and I started to take a little bit here and there when she first started working with it.
At first, it felt wonderful. Clean, invigorating, euphoric, but also somewhat subtle and balanced. I could take kratom and just relax and enjoy existing, or start cleaning my house, or doing chores, or go to work, etc. and it just felt good. I felt an obvious similarity to what opiates were in past years in my life, but kratom just felt different. It felt natural, less guilty, less hedonistic, like I was actually using it for good. It inspired me to do things, which were usually healthy things. I definitely noticed some fogginess in short term memory, but it didn't bother me much.
Nowadays, I take 25-30 grams daily, and have been for about 2 years straight. I'm not even sure exactly when it got to a point that I consider excessive, but eventually I had to concede to myself that I have a new opiate addiction. I get tired all the time, I have very little energy, and my memory sucks. I haven't been able to remember my dreams in quite a long time. I have a hard time even recalling day-to-day activities of past weeks. I have to take it before I go to sleep, and immediately upon waking, and even sometimes in the middle of the night. The withdrawal is among the worst I've experienced, and I'm a former IV heroin user. Seriously, kratom withdrawal after extended heavy use is no joke. I believe it to be just as bad as legitimate heroin withdrawal. However, I have heard reports of others who did far more kratom than me, for longer, who said it was no big deal, so maybe it's just me. But either way, the withdrawal is serious in my experience.
My current relationship with kratom is undoubtedly parasitic. The joy it provides me seems like something that I already had once, and was stolen from me, and I have to suffer in order to receive it back as some sort of distorted "gift". Losing control with my kratom use is one of the biggest regrets of my adult life.
Of course, I'm not convinced that there is anything inherently wrong with kratom; I would never say such a thing about any plant, even the poppy. There is no doubt that it is my own shortcomings that are responsible for what is now a toxic relationship with this plant, but I feel obligated to advise others that it's easier than you think. I have no doubt there are plenty of people who have more than enough willpower and discipline to maintain control over their relationship with kratom, and primarily get only benefits from it, or at least very little trade-off for their benefits, so my mistake was in not knowing myself well enough. But like I said, it's easier than you think. Before engaging in a relationship with kratom, you need to be very mindful of your own tendencies and shortcomings, and you need to stay as much in control as possible when it comes to your doses and repeated use.
My work with kratom originally felt like it was elevating me, raising me up and inspiring me to do more and be better. And now I'm in a very deep hole with it. I don't think I was deceived, or tricked, or kratom is evil or anything, but regardless of the pros/cons of kratom usage, it's a reality that many have to contend with, that they didn't predict.
I didn't mean to write this whole thing just now, but it relates closely to what's going on currently in my life so I had a lot to say. I have just recently started working with Caapi in an attempt to rid myself of the kratom parasite, and I'm optimistic.
To summarize: frequent kratom use BAD, in my experience.