I understand your sentiment, but how about we call “procrastination” what it is: Consistent and repeated non- or under-functioning.
If the person has tried over years so many things, out of the good and best will to function, participate in society and work culture and still fails, why do you still call it “procrastination”? I guess it must be a cultural thing, especially German, to not give the benefit of doubt and just call a medically relevant condition “Faulheit”. I hope you realize that denying the be benefit of doubt - especially after many years of unsuccessful tries, perpetuates the sickness of people and denies them aid that would help them and make them functional again.
Procrastination can be a symptom of deep and challenging mental health issues, some of which have still huge stigma around them. This stigma makes individuals not seek help where actually needed. So please, work on your stigmatization and be more compassionate so that the person might have a chance to overcome their internalized stigmatization.
I mean, the goal here is to turn people functional again, and not bully them, am I right?
Once I went into the actual clinical literature of many various kinds of Cognitive Behavioral Therapy I saw significant improvement in the way how I live my life and how often procrastination encounters me.
The reason why they helped by gaining a very nuanced understanding of how the mind works. This allowed to identify the patterns from a point of understanding and self-compassion ("Ah, see, this is what they meant with perpetuation").
However, that is not enough. You also need constant awareness of these patterns in order to change them. Something that you learn in Mindfulness courses and train with meditative practices and journaling.
So, if I may present a simple equation: Go to the doctor.