I've read Slash's autobiography. It describes his life exactly as one, that is not in the know, would imagine it. That was in the eighties & nineties. Maybe times are different now.
1) Slash is an outlier. I'm sure there are rockstars and actors that spend most of their time doing drugs and chatting up models. There are probably people like this in all fields of life.
2) His public persona is greatly enhanced by writing an autobiography that portrays him as true rock'n roll. It's great marketing.
The truth is probaly somewhere in between.
I play Irish Trad, and I'm as far from a rockstar as you can get, and even I had a groupie once. Once. It was a good one, though. We literally broke the bed. Nuff said.
Unless you know them really well, and you're actually good friends (not acquaintances) just stay the frack away from roadies. Some of them are utter scumbags and their wanna-be ism drives them to do rotten stuff. (Like invite me and my two cool, cute female friends to an "after party" where I end up being slipped a mickey and shoved to the side like luggage and one of my friends winds up with herpes. True story.)
EDIT: No, I didn't wind up with a sore butt and herpes too, thank God.
As an aside, I know many musicians. No one you'll have heard of but a few of them are doing quite well here and could be on their way somewhere. They all have full time jobs and work like dogs. They'll drive 300 miles to do a show and be back to the office at 9am the next morning. To watch them when they're 'on' though, you'd think they led the carefree live of a rock star.
Yes - the music industry is doing significantly worse. I wonder how this leaves everyone.