They are used to exploit known vulns to get arbitrary read write, calls. For cheating. Both freebsd kernel exploits and browser exploits.
Weird to see this is still a thing on the latest console generation. Xbox runs software under HyperV which should make exploitation difficult
Also for rooting the console, which makes it way easier to run cracked games. I think I saw a browser being used for getting root access first with PS3 unless I misremember.