'Filler episodes' apply to serials. I think audiences forget that every thing that isn't a sitcom isn't made like a serial (with a lot of shows mimicking soap operas where a story may be connected and move but arcs just blend with no end in sight).
If you take Mando with its western and storybook style it has no fillers. It plays out like the story of a fabled gunslinger/bushido who ventured all over the place while slowly making a legend for himself.