For example, a Kithkin card printed with "During your turn, this creature has first strike" is not considered to have first strike as a printed keyword ability
If you ask me, it mostly comes down to the last line of text
11 Zada, Hedron Grinder The Best 2-For-1s Zada is a strange commander that both rewards playing lots of spells and having as many creatures in play as possible
Fun value and financial value arent the same thing, and the right choice depends on what youre optimizing for: pulls, art, nostalgia, or long-term value
Theres also the fact that these cards are not unique to a set, in terms of their actual stats and abilities
Thus a card that dominated the formats it was legal in or has regular play in Modern or Legacy like Atarka's Command, Wild Cantor, Burning-Tree Emissary, Huntmaster of the Fells, Manamorphose, or Bloodbraid Elf, would still need to prove it's chops at the kitchen table