This was me too. I had used many substances (cannabis, ketamine, benzos, cocaine + every other stimulant under the sun) and was able to keep them in my possession and only use them at most once every 4-6 weeks, and only ever in the company of others. This lasted for many years. I was arrogant and thought I was above addiction. I tried heroin and was addicted before I finished my 1g bag.

I think your point about "stop[] scheduling every drug as equally dangerous" is very salient. I really don't want to shift blame anywhere but myself, but if society had been honest about treating heroin as much more problematic than (for example) cocaine or amphetamine, maybe I would have listened. But when they were all considered equally bad and the others didn't form a grip on me... you can see how I ended up where I did.

Thankfully, I had every advantage one could need: a loving spouse, a lot of savings and a medical system that treated it as a health problem, not a criminal one. I told my doctor about my addiction and he prescribed diazepam for the withdrawal. He wrote a referral to admit me to a psychiatric hospital. I was able to take a month off work (and keep my job) while under the care of professionals. Without all of those, I'd probably end up dead in a few years.