What I got out of it was that plant life got diseases that killed them/made them unedible and corn was the only one holding off until the start of the movie. Also in my extremely slim understanding of planetary modification you need to release gases (carbon dioxide, oxygen etc) on a planet to create an atmosphere and it’s way easier to release gases than remove them.

So their plan was to let the earth crops rot away and plant fresh ones where there is no diseases.

Imo it is way better than what OP made it sound to be, held my attention whole way through.

I just watched this! It felt like the director wanted to go real big with it but technology just wasn’t there with effects. It also tried very hard to be a mindfuck movie but also kept spoiling the twists somehow lol. Overall solid 7+ movie.