-Why did Genesis not have an "eject" button?

-I've heard that "pulling an SNES game out" withOUT using the eject button causes harm to the game. IF TRUE, why doesn't this apply to Genesis games (which obviously require to be taken out manually?)

-How has your SNES eject button hold up over the years? What happens when the button "no longer functions properly?" I guess this goes back to my question of "does yanking an SNES game out without using the eject button do any harm to the game or system"

I tend to leave my SNES games in for as long as I can -- I want to avoid as much wear and tear as possible -- or am I just being a bit paranoid? I like to play a game and stick with it (partly to fully enjoy the game, partly to perserve the eject button -- I've seen SNES models where the eject button died out)

I guess that's all I have on my mind right now. I always meant to ask these questions but never got to it. Any insight is appreciated! Thanks.