In the '70s, everybody was doing drugs, so long as you showed up and did your work, they'd use you until you died.
Showing up every day isn't enough. There are a lot of guys who show up every day who shouldn't have showed up at all.
I was trained by Method acting teachers and we were taught that aside from whatever gift you may or may not have or the level of that gift, that you were obliged to know how to build a table. It's a craft. It's like being a ballerina or a violinist.