Can i somehow get to use all mobs without trying to kill them all? (not in creatuve)

yes, but you would need to use commands for that
/identity grant @s [name of entity]

this is the format of the command,
you would need to type every single mob's name yourself, as there is no way that I know of that can give you all entities

(this topic should be on the discussions tab, as this is not a bug)