I think the rigidity of this anime is both its strength and its weakness. Cells at Work is an anthropomorphic portrayal of the inner workings of your body, where every cell is a person, every bodily process is a machine, and every bacterium is a monster. Every episode is self-contained and teaches a new lesson about how our bodies work.
What this means is that we see very little character development over the course of the series, the episodes sometimes don’t feel connected, and you’re constantly suspending your disbelief about how it all fits together.
However, that also means the episodes are very consistent, the writing is rigorous and accurate, and show is always finding real human drama in the ways our real life bodies respond to problems. On top of that, the animation is excellent, the stories are funny, and the opening theme is unironically amazing. I watch the dub and often find myself singing the theme to myself during my day.
This anime does exactly what it intends to do very, very well. If that isn’t what you’re into, I don’t think it will win you over, but if you can meet the show where it’s at it’s a bucket of silly fun with a bit of education thrown in.