I owned both as a kid. My grandma had got us a Sears arcade ii with 30+ 2600 games from a garage sale around 1986 or so. I remember watching my dad be able to beat pitfall ii and it seemed impossible. The system broke so we got a 7800 thinking it was just a replacement and had no clue it played better games as pole position ii never really made me think it was that much different. The only new games we bought were 2600 games (Pac-Man jr, skateboardin’, Mario’s bros, realsports football).
My brother got an NES for his bday in 1988 and I pretty much never played the 7800 for years. We didn’t get Super Mario with the system but we picked up castlevania and mighty bomb jack with Zelda being our 3rd game I think.
if I would have known better as a 7 year old I would have picked up robotron and found a way to bolt down both controllers for some dual shooter action.