2010 Prius uneven rotor wear and brake codes

You wrote that the picture is "driver's side rear rotor", which would be the left rear. Trouble codes C0210 and C1238 are for the right side rear speed sensor. So it appears that you have two separate issues to fix.

Trouble code C1214 is " Hydraulic Control System Malfunction ". Possible trouble areas are:
1. Bake fluid leaks.
2. Brake disc rotor excessive wear.
3. Brake booster with master cylinder (Brake actuator).

When was the last time work was done on the rear brakes? Where the brake pads replaced at that time?

 

The uneven rotor wear is very likely due to misaligned caliper piston. More info in the rear brake drag link in my signature (on a phone turn it landscape to see signatures).

 

Soon as you pull the caliper off and the caliper bracket and the rotor because that rotors coming off you'll get new ones and then you'll see the slides or something are not operating properly you should be missing most of the brake pad at least the one we're looking with the narrow contact facing us that ought to be quite good stuff no brakes should ever look like that that is horrible but they do so there's always that pull the mess apart and take a picture of the junk that's laying on the ground after you have it all off the car and laying on the ground You should be able to clearly see what needs to be done but apparently that is a gift and many people may not have it I don't know to me it's just common sense but anyway once you have the parts laid out and on the floor it's pretty much a no-brainer You don't have to buy all that stuff at the Toyota dealer it's all marketed by everybody now there's none of this stuff is new enough to worry about no cutting edge about any of this at all and yes the sensor for the electronics is built into the rear hub so if it's messed up in the hub you're getting a new rear bearing that's how you get the sensor The fronts are individual and stuck into the big piece of aluminum and read a tone ring through a slot the rear not so much.