Animorphs Book 50: The Ultimate by K. A. Applegate

Cassie struggles to relate to the parents' perspective on the war. The Animorphs expand their numbers. Tom and Jake have a showdown and Cassie intervenes. I really like the new Animorphs, and having this much shift really ramps things up.

I like James and the others, and I don't agree with everything Cassie does in this book, but I understand it. There are a lot of exhausted and stressed conversations/decision here, as well as a disconnect between people reaching for perfect vs good enough. Jake is exhausted. The phrasing throughout these books makes me think the whole series might take place in less than a year, two at the most. I don't remember if this is ever confirmed, but Rachel talks in terms of having fought battles for months, not years.
* A small dive into Seerowpedia reveals that they've been fighting for several years now.