AZ Transportation Engineers - Proposed I-11 Route Bypassing Phoenix

Question for civil engineers about a proposed Interstate Hi! I am an independent journalist, and I am currently working on an article about the new proposed Interstate 11 freeway in Arizona. This is the current suggested route from the Arizona DOT, and I am curious as to why the proposed route completely detours around Phoenix. I am not a civil engineer, but as someone who lives in Southern Arizona, I don’t understand the logic here for any of this proposed route. I have spent the last few days trying to answer that question, and I reached out to the Arizona DOT for comment, but the only info they gave me was a copypaste from the publicly available info on their website. I would love to get some input from people who understand this better than me. Thank you!