Cancelling a treachery's revelation effect nearly translates to putting it straight up to the discard pile.
Some key words aren't part of the revelation effect, currently including Hidden (though it has little effect on its own), Peril (you can't cancel another player's treachery with this keyword, though this is more a Ward of Protection (2) problem) and Surge - yep, you're still drawing another treachery, even if you cancel this one! Obviously except the very rare occasion where Surge is part of the revelation effect such as False Lead or Snakescourge.
Anyway, apart from that small rule clarification, Ward of Protection is in my opinion one of the best cards in the game and I automatically take it with any investigator who can. 1 resource, 1 horror and 1 card is nothing compared to cancelling a treachery that your investigator can't deal with, that would lead to a defeat, or that would simply cost too much. A striking example, in a 4 players game, Ancient Evils would rob your team of 12 actions... Well, not with Ward of Protection!
The level 0 version is obviously a lot less strong than the level 2 version, the later being able to target any investigator anywhere, but it does the job. Ward of Protection is never going to sit more than a few turns in your hand, and if it's sitting in your hands it means that you are not facing any really problematic treachery, so that's actually fine.
On top of being super strong, it comes with a icon. You'd really rather play than commit Ward of Protection, but if you need to there's that.
It is also a totally fine card even when it eats an investigator's wild slot (such as Dunwich's investigators) if you can't be bothered theory crafting / net decking for ages trying to find the very best card for these wild slots. You'll always get value out of it.