Despite not being able to break blocks with a sword or trident in Creative mode, you can still see the hitbox as if you were able to. However, in spectator and adventure modes where you are also not able to break blocks, you cannot see the hitbox. In addition, attempting to break the block causes particles to appear.

1. Spectators do not see the hitblocks of blocks. 
2. Players in adventure mode do not see the hitbox of blocks. 
3. Spectators and players in adventure mode occasionally see the particles produced by breaking blocks.  (MC-215163)
4. Players in creative mode holding tridents or swords do see the hitbox of blocks and particles. 

Note: In adventure and spectator mode, particles also appear, but is due to MC-215163, and you won't see the hitbox.