That’s just how sets were designed back then; a ton of variations on the same design. Mirrodin has four different black creatures that get +1/+0 for each artifact you control. Vertical cycles (similar cards at each rarity) were a lot more common. The planeshift self-bounce creatures have the...
Modern delver decks managed to exist without wasteland before fatal push was printed. One thing that helped create “small game” magic during that era was that most answers simply weren’t tempo-efficient; only red had removal that you’d be happy to point at a delver or equivalent at the necessary...