But vanish is a very powerful skill IMO.

Think about all the traps you can escape: entwine, cutoff, parting block, stsf, locked rooms, centurions, avoiding a (deathblow) parting blow, the list goes on.

Hell it works when cursed or in cursed areas making it arguably better than word.

Plus you then have all the navigation utility of potentially moving through areas quickly, bypassing doors, getting to hard to reach places, etc.