Nah, you can bounce back for sure. I've gone down some pretty deep holes in my life. Now, while not sober, I certainly have my shit together much more than before.

People can change. It is genuinely difficult in the moment to recognize certain behavior as unhealthy and changeable. Sometimes, when you're in this lifestyle, it feels like the only way to get through the day.

Some people won't ever get better. Some will be good for years and then go back. Some people won't ever have real issues/repercussions from this while others will hit a bottom within weeks. It really just depends.

Also, while maybe not the case for the people you know, it's important to know that some of these people probably have some other severe issues. Maybe, despite being so detrimental, this lifestyle is better for them than what they previously lived though. Some people just grow up in pain, with terrible families, suffering years of abuse. Some others have mental issues and no real good way to cope.

People get clean after decades of use. It's not common but it happens.