I would need my memory refreshed, but if you just played that episode cold for someone who didn’t know anything about the show and you didn’t tell them anything, would they know what the meth lab is and why he’s there? That might be a rather vexing question.
Yeaaaaaa… I don’t think that episode works as a standalone.
If I’m understanding the OP correctly, there are lots and lots of examples of TV shows that have no story arc between episodes and no common ongoing context that the viewer needs to know about. Every episode is its own story, with its own characters and actors and is effectively a short film. I’m currently greatly enjoying The Alfred Hitchcock Hour as late-night bedtime viewing, and each episode is exactly like that, essentially a 50-minute mystery film, with elements of film noir and the occasional rare dash of the supernatural.
Aziz Ansari’s series Master of None had an episode that consisted almost entirely of loosely linked vignettes about random people around New York, with the main cast members only appearing briefly at the start and end. It was either a loving homage to or a transparent rip-off of High Maintenance, in which every episode was “effectively a short film.”
Clearly by definition anthology shows would fit the brief but I was talking about shows that are episodic and have continuity of characters (normally). Several good examples already in the thread.
I will give another example. The episode Hush in Buffy the Vampire Slayer. There is some stuff you would miss or be confused by but I have a friend who has watched this episode and no other several times because they enjoy it as just a horror story.
From the 1940s until the 1960s, many American television shows were anthologies, where each episode was a story by itself with no relationship to other episodes. Even after that time, it was common for each episode to be about the same characters but with no changes in their lives over time This made it easy to watch the episodes in any order. By the 1980s, there began to be character arcs, where the character underwent changes in their lives. This became more common in the 1990s and afterwards.