I grew up in Rock Hill schools and my children currently are in RH elementary schools. I see no issues with them. You have the choice to go to the nearest neighborhood school, or you can go to a school of choice like montesori, STEAM, spanish, french, advanced studies, etc. See here:
https://www.rock-hill.k12.sc.us/Page/5064
RH has recently spent a lot of money renovating a lot of these schools and pushing for school of choice, and from what I have seen all the elementary schools all run about equally. RH tends to apply policies evenly across all of them.
There are also two charter schools...York Preparatory Academy and Riverwalk Academy. I don't know much about them, and they are fairly new.
There is one private school...Westminster Catawba Christian School. My niece went there.. they are a bit expensive.
Historically Fort Mill schools were better due to Springs Industries pouring so much money into them. But Springs isn't a big employer anymore here and Fort Mill schools have a ton of new people moving to the area so I have no idea how well they are keeping up.