I started consuming kratom about 4 years ago.
At first it was a wonderful feeling, then that feeling diminished until it became what it really is: a medicinal plant with many virtues.
In my case I consume it daily because I discovered that it greatly improves the absorption of sugars and improves insulin sensitivity, which greatly improves a diabetic-life, it also greatly improves mood and optimism, and makes you more understanding and calm, in social relationships. I would also say that it is the best substance to take if you have a physical job such as working in agriculture or any hard, tedious and repetitive work, cause it greatly improves physical endurance, and it is a substance that shines when one is in motion.
Tolerance grows in two ways both improvable, almost impossible, to avoid so to speak.
The first is that of euphoria, even if you consume every week once or twice, the euphoria will be less each time, your brain gets used to it and the sensation of rushes (although small at the beginning) are less and less frequent. The other has to do with the daily consumption and especially the consumption every x hours (multiple doses a day). If you enter into such consumption tolerance will grow a lot and the psychological aspects of kratom will be less and less, although in my case they have not disappeared, they are just more smooth. It is a substance with an incredible antidepressant capacity, the best I have tried and my girlfriend too (more important in the case of my girlfriend because she has taken Rx antidepressants, many different over the years, I have not). Sadly, if you want to keep the stimulant parts of it alive you will need to replenish both your dopamine and your adrenergic system (adrenals) as often as you can, some people take agmatine for the mu-opioid balance (nmda activity) and I would take anything that support the adrenergic system like ashwagandha (sure some people will know more than me on this).
Tolerance after a few months of taking them daily can lead to withdrawals. Interestingly, for me the first time I suffered them was the worst by far: a lot of fatigue, nervousness, anxiety and slight depression, some tremors and restlessness, snot and sneezing. The first time I went from 12 grams to nothing in a day and a bit. Right now I take about the same amount a day 8-12 grams a day, and have little trouble when I cut: I space the doses so that I go to taking 2 times a day instead of 3-4, then a couple of days taking 2, dropping 1-2 grams... and finally jump to zero from 3-6 grams, taking the last dose at night. The only thing I feel is very slight restlessness, trouble sleeping (I use ashwagandha and l-theanine when I cut and it fixes it) and some tiredness and lack of motivation (I use mucuna pruriens for that). Another VERY useful plant for kratom withdrawals is black seed oil, a couple of teaspoons a day.
In general kratom has to be considered a master plant in the sense of being a great medicinal plant, with a certain "spirit" that you learn from, in a way perhaps similar to calamus, but more versatile and more stimulating. In my case I do not consider it a drug although it can be used recreationally, that is not where it shines. The withdrawals are very mild, if one knows how to disconnect correctly and use it with moderation.