First, Ramp decks don't play many cards that can be easily interacted with
But even a couple turns of that lock can completely stall explosive decks and buy you time to stabilize
I personally did not include them in my top 5 picks, since I believe that there are better and more impactful lands in the format, but especially players who prefer to play aggressive strategies cherish them and will probably disagree with me
Meanwhile, in mana-hungry decks with Arboreal Grazer, its easy to set up an attack with your 0/3 to get yet another extra land into play
The only downside with this card is that it costs nine mana, which isnt cheap at all
Gray Merchant of Asphodel The weakest body by far on this list, with this card you are almost entirely paying for the effect