I disagree that anyone is in a position where it's literally impossible to stop. It may be figuratively impossible or metaphorically impossible, but I think if you really think there was any point where it was literally impossible to stop you're either deceiving yourself or misusing the word "literally". Can quitting at times be extremely difficult? Yeah. Can it feel impossible? Of course. Is it literally not conceivable? No.
I agree with the general ethos of harm reduction, however. Of course, if your choices are to either continue your escalating dose and using as much as possible or to cut your dose down, then cutting down is preferable if abstinence is too difficult at that point in time for whatever reason. However, there's a reason that abstinence underlies not just 12-step meetings but practically every recovery program, including Refuge Recovery and secular ones like Smart Recovery, and it's because moderation is harder for addicts than quitting entirely. Once those neurons have been intertwined with the concept of your drug of choice and you are used to using in an addictive way then it will be extremely difficult to enforce limits. It's possible, of course, but it takes insane willpower & self-control, & if we had a lot of that to begin with then we wouldn't have our drug dependence!
Note that I'm not a 12-step acolyte who dogmatically insists that to count yourself as "sober" you don't just have to stop taking your DOC but methadone/subs, alcohol, weed, prescriptions etc as well (but with a curious blind spot for cigarettes, coffee & donuts....). I think that approach has caused an awful lot of harm, as has many of the AA precepts that have become part of the recovery culture (for example, the insistence that one slip will inevitably lead to an awful binge has I'm sure caused many an addict who may have briefly slipped to think "fuck it" and go on that bender, making it a self-fulfilling prophecy), but I think one of the concepts that they have right is that moderation is a lot harder than abstinence in the long-run. This is just about the practicality of it as well - this isn't even to mention the fact that without abstinence we don't give our brains a chance to heal and so suspend the physiological/biochemical process of recovery so that even if our physical/material conditions improve with moderation, the emotional state that leads us to using will remain identical.
However, I'm pleased that you are harming yourself less than you were. Like I said, I am a big proponent of harm reduction - I just hope that if you want to overcome your addiction then you have some eventual plan for abstinence to give yourself the time & space you need to get better.