The leap from Super Mario Bros to Super Mario Bros 3 is divine. Don't even start talking about 2, depending on what you're talking about it was either an expansion pack or a cobbled together filler episode. SMB1 was the foundation of what would be considered the default video game for some twenty years, and only three years in, SMB3 decided to be the peak of it. Nintendo had struck gold in '85 and by '88 they had mined every particle from the vein.
Those three years had already spawned a legion of imitators, and as would continue to do in the future, Mario would humiliate them all just by walking back into the room. SMB3 leaves the first game's pretenders naked and embarrassed. It is the complete realization of the Famicom's potential, and it is as perfect as a Famicom platformer could possibly ever have been. It is a game that is limited exclusively by time and place. By the fabric of the reality it has conquered. It is the best game on the Famicom because it is the best game even theoretically possible on the Famicom.
Those three years had already spawned a legion of imitators, and as would continue to do in the future, Mario would humiliate them all just by walking back into the room. SMB3 leaves the first game's pretenders naked and embarrassed. It is the complete realization of the Famicom's potential, and it is as perfect as a Famicom platformer could possibly ever have been. It is a game that is limited exclusively by time and place. By the fabric of the reality it has conquered. It is the best game on the Famicom because it is the best game even theoretically possible on the Famicom.