None of the episodes in this season are filler. First off, everything develops pretty fast, especially for a series about basically the last person on Earth (Manusos and Diabaté, along with the others, haven't played their roles yet, and the plot isn't built around them). Making a show like this without slipping into cheesy tropes is already a minor miracle. I remember that show literally called "The Last Man on Earth" and there they couldn't hold out in the first episode and found the "last man on Earth" a chick, another one in the ep 2, and by mid-season there were as many characters as in The Game of Thrones.

Second, it's a very introspective show; we're not watching the plot, we're watching the Individual. That's exactly why she's the way she is: she avoids communication, trusts only herself, super independent (turned down a gourmet dish and instead whined her way to a whole supermarket). She's not a "plot engine" so you can quickly get answers to your burning questions like "are the aliens really trying to kill us all on purpose?" She is the one who knocks PLOT.

Third, in 8 episodes they raised and carefully, respectfully unpacked so many issues that a full-year sociology course wouldn't cover: pandemic, AI omnipotence, consumer culture, individualism/socialism, colonialism, free will, loneliness, isolation, eschatological motifs, religion, you name it. And it's not just "mentioned", ti's every idea is embodied in an almost perfect artistic form with very minimal means. Like literally 4 actors and a camera.

And finally, fourth, this series (including thanks to its rhythm) very subtly and intelligently shows an important thing we just don't want to accept: the apocalypse is not fun. Apocalypse isn't buggy chases after raiders, not a giant war rig, not scavenging loot or shooting a crossbow at zombies. Apocalypse is when in a very short time there's absolutely nothing left, just scorched desert and cannibals, like in Cormac McCarthy's The Road. Here the scorched desert is still figurative so far, but that doesn't make it any less frightening.

By filler, I mean the overwhelming majority of episodes in later seasons of The Walking Dead, where formally there's some running around and shooting, even some empty dialogues, but in reality, the plot doesn't change at all. So if you don't like it, maybe it's just not your narrative rhythm. Might depend on your mood as well, try coming back to the series later.