This datapack makes it so falling into the void drops you back into the overworld. Your coordinates in the end are transferred over to the overworld when you fall, and you are dropped at y=300. This only works on players because of performance reasons, but if you'd like to make it work on all entities go into the folder and into data > void_drop > functions > main and replace '@a' with '@e'. This will make it work for all entities, but may cause slightly more lag on lower-end computers.