StarBunnie

If you give them the permission to do so they can just teleport to any world at will

I recommend making an extra command like /survival or something

command /setsurvival:
 trigger:
  player has permission "survival.set":
   set {spawntp::survival} to location of player
   send "survival tp set"

command /survival:
 trigger:
  teleport player to {spawntp::survival}