is nbtexplorer safe to use on a newer minecraft world?

for small edits you might not need an editor at all. /data get and /data merge cover a lot of it in game and always write the format your version expects. for bigger jobs on a whole world people tend to use Amulet now.

I wouldn't trust it on anything recent. It hasn't been kept up with the format changes, and item data got reworked a lot in the 1.20.5 update, so it can read things fine and then write them back wrong. If you do use it, copy the whole world folder first. For small changes like a player's position or an item, the /data command in game is the safer route.