Thank you for the suggestions.
I think I realize the problem after reading many of the posts. What's slowing these devices down is the management software running over them. GoGuardian and whatever else IT has on them.
We also aren't allowed to use an ad blocker anymore. I used to have Ublock installed on all the devices before GoGuardian prevented it. It's a really depressing situation that I imagine will only get worse with time.
As to a few replies asking why students in this age group would need laptops, I'll explain. I start teaching Python in 6th grade. Grades 3-5 use Scratch. Grade 2 uses code.org. K-1 Scratch Jr on Ipads.
We have expensive mac desktops in the computer lab but they drive the students completely insane for two reasons. The keyboard is and mouse are terrible to use. Anti-ergonomic. The second reason is the amount of notifications and questions the students are bombarded with when they turn the macs on. I'm talking like 15 different pop ups or windows opening asking them to agree to this or that. I should probably have a lesson on just closing windows. I could say more but I don't know about social media anymore. I just wanted some suggestions and I appreciate the ones I received.
I don't know your autonomy with regards to IT within the confines of your classroom but if you can't install ad blockers on the Chromebooks can you set up something like PiHole and direct DNS traffic through it? It won't solve the overall slowness of the Chromebooks but it will help with some web sites.
You should open the issue with your IT department and see if they can optimize the performance. You can gather proof that GoGuardian is causing slow downs by looking at it's memory usage in the Task Manager (right click empty area in Chrome tab bar).