The frequency and value of holographic cards tends to vary from game to game, but rare holo cards can be highly sought after in their own right
Other than that, it can be used for Nazurvist with Revolution Synchron when passing through the junk speeder
Monster Tokens may be used as Tribute or material for Special Summoning methods (except Xyz Summon, as Xyz Materials are not treated as being on the field), but cannot be used to pay any cost that involve a monster moving to a specific location (they can be banished, as the banishment is not considered a location, but will still disappear permanently since they are leaving the field)
Achieving a single PSA 10 card is incredibly difficult, let alone collecting an entire 102-card set where every single card hits that top-tier grade
While this does not seem like much, it is an excellent way of getting damage counters on a Pokemon you intend to hit with a power-scaling move