It is a huge problem. PR reviews are a big deal, not just for code reasons, but they are one of the best teaching tools for new hires. Good ones take time and mental energy.

Asking me to review a shitty PR that you don't understand is just disrespectful. Not only is it a huge waste of everyones time, you're forcing me to do your work for you (understanding and validating the AI solution) and you aren't learning anything because it isn't your work.