Fentanyl is just plain bad news. It's not a coincidence that we started seeing an explosion of homelessness and fentanyl use at the same time. And unfortunately progressive advocates for drug policy reform and homelessness basically have to ignore this reality, because it makes their preferred policy positions untenable.
If they admit that fentanyl is a major driver of homelessness, then it's impossible to defend a "housing first" approach to homelessness. You can't just give an addict a free apartment in a big city and expect everything to work itself out. Fentanyl throws a big wrench in that.
Neither can you just stop enforcing drug laws and expect that society will be better off as a result. Because fentanyl fucks people up, and fucked up people do fucked up things, and that's why we have police.
Housing first and decriminalization are great policies when the worst thing you have to worry about is cocaine or heroine, and the access pipeline to them is fairly limited. But America's pharma companies were all too happy to create a bunch of new opiate addicts with oxycontin and the like, and then cut those addicts loose so they had to get their fix somewhere else once their prescriptions ran out. This addiction pipeline just didn't exist with earlier drugs like marijuana, cocaine, etc.
Unfortunately these policies came onto the scene about 15 years too late. We do need enforcement as well as treatment, and we should be making pharma companies pay for it.