Nothing I hate more in a show that the characters going into a lounge and an episode spending a significant amount of time just showing the singing act. That is just shameless filler - painful when binging.
The only thing worse is episodes that go nowhere or don't advance the plot. Although if done well independent, self-contained one-off episodes can be rewarding if done well. I give the diner episode a pass for that reason.
Funnily enough, I always kinda like that stuff. Not just lounge scenes, but any time a movie or TV show can mainline some pure atmosphere and just soak for a bit, I'm in. I would agree with you where it can go on for too long, and should ideally be more tied to the storyline, but I don't mind the smoky cocktail lounge singer digression.
Now, filler episodes? Absolutely. I was rewatching Ozark recently and there's a flashback episode that wasn't great the first time through and really dragged on the repeat.