>>720172542
The Sonic mythos had the depth of a kiddie pool outside of SA1. The introduction of SA2 greatly expanded what Sonic had to offer. Shadow and his story expanded what Sonic was allowed to be.
We could have epic stories, actual death, betrayal, redemption, character depth. Sonic had a WORTHY rival. Knuckles was and continues to be a nothing character so he couldn't carry that role. Mechanical Sonics had no real character to them before until Metal Sonic started becoming more villainous, having more depth, and acted more like an ACTUALLY evil Shadow.
SA1 deserves the credit for introducing more than surface level lore, monstrous and epic creatures, and genuine consequence with the destruction of cities.
SA2 elevated all that and truly expanded the franchise into all directions.
Without SA1 and SA2, the series would be just living in Mario's shadow.