I think the appeal of them was never that they had great, enviable lives. Ginsberg's famous refrain is that he saw the best minds of his generation destroyed by madness. Doesn't that resonate so much with young people, especially today, who have all the acumen, follow all the rules, and end up priced out of any kind of normal middle class life? Sure it's not the same thing the Beats faced, but isn't the idea of seeing a society from the outside and never being able to join (or for the Beats, wanting to join) isn't that common?
They were talented writers who didn't fit into the times they lived in, and who made choices that made their lives worse (and documented them extensively) and who reached for drink and drugs (and Eastern spirituality) to numb themselves at being in a world which they felt so apart from. How much different is that than many famous writers across many times and places in history?
Ginsberg as you noted also had his moments of literary height. And I can appreciate some of the artistic merits of Burroughs' work as well, though as you note, he was either a sociopath or at least incapable of critical self-reflection in his writing.
On the Road, for whatever reason, was a complete miss for me.