Although Lovely Boy tells a story of drug addiction through the lens of contemporary culture (trap music, social media etc.) there are those who might argue how it doesn't offer anything essentially new. And although this complaint might hold true, I dare say the omnipresent sexual promiscuity and substance abuse in the entertainment industry of today make such a discussion futile.
If we compare Lovely Boy to other famous movies that explore a similar topic, for example, Trainspotting (1996), there is absolutely no humor here. And if you remember Requiem for a Dream (2000), you'll find a very similar message, told in a much subtler manner. And, thank God, we're very far away from Christiane F. (1981).
If you like comparing, there are some similarities with Youth (2015) and The Hand of God (2021) by Paolo Sorrentino, obviously, not in a nice way.
The main protagonist comes from what seems to be a middle class family. His parents even support him in his pursuit of a music career and are trying to come to terms with the accompanying lifestyle. To put a long story short, Lovely Boy chose his path to hell and back himself.