Just a counterpoint, I loved Project Hail Mary. I wanted my time back after reading Children of time, and it's exceptionally rare that I feel that way about anything scifi. Tastes differ. ::shrugs::

I really loved Children of Time but then he really went back to the same well for the rest of the series

Yeah the sequel ran with it decently. The third one was a slog and that ending ... Ooofff.