I'm not sure what to think about how arcade-y Sonic is, or how different Mario's impact on game design was.

But when I played the Sonic games, I didn't think of them as games where I should memorize the layout in particular.
Although it was obvious why that would be beneficial, I just didn't think I'd get the chance to do so. And I didn't, thanks to the infinite health system you mentioned.

Not dying often lead to me not replaying the stages often either. So I was mostly getting through them an a less efficient manner.
And I still had fun with it that way.