Server side can not do anything about ESP or aimbot as they rely only in information that the server must provide the to the client. ESP can be curbed somewhat by obfuscating objects not in their view, but how effective this is depends very much on map geometry as the server must send it at some point. It works okay in games like CS/Valorant (that already has it implemented for years) but does basically nothing in Battlefield/Apex/Escape from Tarkov as they have very open maps. Aimbot can be configured to be pretty much indistinguishable from the best players.