Competitive players flocked to this card because of its game-changing effects in TCG battles, making it one of the rarest and most valuable non-Pokmon pulls in the set
Your one Narset in the same spot
This, at least in part, probably explains the higher deck price, although to be fair, if Legacy is your primary format, new players have to buy a Legacy deck if they want to play, so the comparison to Magic's Standard seems reasonable
An attack with just a single creature is enough to spread counters around
Due to how powerful Dragons are, you often don't need interaction in the first place
Sliver/Elf deck is pretty dangerous, it solves Slivers biggest problem, consistent early game ramp