Should be able to disable mob spawn for unique mobs

I think it would be great if mojang added a new command like “/disable mob spawn @e[type=slime]” this would make slime not spawn in your world naturally (ofc you can do it to other mobs besides slime) or maybe you can also disable these mob in the making of a fresh minecraft world, so that specific mob you chose will not spawn in, except you can put summon the mob you disabled via commands, when i meant this command i mean they will not spawn ‘naturally’ which means it is still possible to spawn the mobs you disabled via commands.