I finished the Project Hail Mary audiobook like an hour ago. I'd seen some commentary/complaints that the movie is a soft scifi, at least by comparison to the book, and I can see the case for that argument. However, I think those changes make sense and serve a solid purpose - the film values the emotional throughline of Grace's personal growth and interpersonal relationships (particularly his friendship with Rocky) more than the science competency porn.
I think the changes translate to a better film experience - the movie is already long and getting too bogged down in the details of the How vs the emotional beats of the Why would take away from the emotional impact. I can totally see why, especially if you read the book first, you'd be disappointed by those omissions. Cutting the detailed science competency porn has a significant impact on Grace's characterization, but some of that may just be Gosling's performance. He's a little goofier, a little dumber for the sake of some humor or speeding the plot along, but also he's so endearing and the core personality is similar enough that I don't mind it. I think Carl was a great addition and helped fill the void left by cutting all of Grace's interactions with various scientists on the project to decrease runtime and kept the film's focus on the relationships we form with others, particularly in the context of the end of the world.
Basically, I think the changes make sense for an adaptation to the film medium. That said, I'd LOVE to see ALLLLLL the cut material and science-y shit.