The CPU is soldered on this, along with all of the Chromebooks. In addition to that, you need a Xeon ready mobile chipset which is typically only found in the likes of the HP Zbook/Dell Precision/ThinkPad P Series ISV certified mobile workstations (Hint: ALL of these are considered “high end”, although workstation is often interchanged with the term “workstation” for standard PCs), and it’s still considered an option with all 3 vendors. In addition to being an add-on upgrade, the cost to get a Mobile Xeon is not cheap due to the cost of the CPU+chipset pairing required, often needing a entirely different motherboard. Your parents aren’t going to buy you a Xeon laptop for school.
You only see a subset of the used population with Xeon parts due to the cost for a reason - most people get Xeon sticker shock, and because of the amount of Xeon vs Core i models Xeon machines fetch a premium :-(. Believe it or not, I’d love to own a Xeon Zbook 17 (Dreamcolor LCD), but they’re already expensive with the i7 used - add on a Xeon motherboard… OUCH! The option already hikes a NEW Zbook 17 into hollywood/bulk college fund prices due to the low upgrade rate when the machine was new, regardless of OEM.
You can also load the Xeon machines with a ton of RAM - some max at 128GB, with others going to 256GB with 4 DIMM slots. As tempting as it sounds, you don't need it as a student - it’s only sensible for a small percentage of people. An example of when it helps is say I ran 4K XVAC video or processing RAW images off of a high end mirrorless camera through the laptop (AND I am running it through Adobe Premier or Photoshop CC) - this is where Mobile Xeon shines, not Google Docs school work. The Celeron is plenty for an average student with a Chromebook! I wouldn’t need 128GB, but I’d probably spring for 2x32GB on a 4 DIMM machine so I can bring it up from 64>128GB easily.