I know this is probably a common topic. For me, I’m not sure if it’s a “trope” or just totally misinformed writing, but it’s how many authors approach alcoholism. Some examples are Girl on the Train and The House Across the Lake, among HUNDREDS. If anyone else here has struggled with alcoholism, you know it’s not just "i woke up after downing an entire bottle of whiskey but was able to shower, down a cup of coffee, and solve a murder. "
Your post reminds me of the book Fiend. It’s about two meth heads who experience the zombie apocalypse. Great depiction of drug addiction. And they’re also realistically incapable of dealing with their situation.