Second I'm not sure on your target on your 2nd point, since I've been straight edged for like 10 years. Vices really don't do anything for, getting drunk/high/whatever does nothing for me when you're just gonna be in the same position you were when it subsides.
My second point is about replacing reality with good feelings. I used to get high on New Age beliefs, and coming down from that was hard. I eventually learned that there were no guides, that I didn't choose this incarnation to learn lessons for my soul to grow, and that I don't have a purpose to make the world better. I used to smoke weed, too, and it put me in a temporarily good mood when things were shit, and it sometimes got me through, but reality is still shit, and so I needed better tools manage the shit if I remain in reality.
Which leads to my third point of either finding tools or getting out. The tools I've found are some energy psychology techniques for managing and healing trauma, and Stoic and secular Buddhist philosophy for managing the realities of life, including suffering and all the things you pointed out that you see (which it seems that someone you know labeled nihilistic). Stoic philosophy also taught me that sometimes the most rational response is to withdraw from life, to neither cling to it nor to flee it, but to exit calmly, especially if conditions are such that one has no power to be themselves, or to practice self-control or virtue.
Those conditions, according to the Stoics are tyranny, ill health, poverty, and "madness," as well as coming to the aid of an old friend who needs you, which was, for them, their government which protected them and their society. Governments certainly don't do that now (if they ever did), at least not when viewed according to how you seem to view the world. I was in total agreement with how you view the world, and it breaks my heart.
If that still didn't make sense, it's on me, not you. If you ever want me to clarify further, I'll be glad to, and if you just want to move on from it, I'm happy to do that as well.