Sure, as most of those were 16kb-64kb carts, weren't they? Amiga games were all over the map, but most were closer to the 512kb+ mark. That would have made for one extremely large, heavy, bulky and expensive ROM scenario back then.
Yeah, even a 4megabit cart in '85 probably would have been almost unheard of. Begining of the 90s 4mb was becoming common, then Stryder on the Genesis came out with it's 8MEGABIT cart!! They advertised that everywhere. I was like, 1 megabyte? I've had Amiga games bigger than that for years!! ;-)