In the case of #1, you start to lose your association of fake or staged sex acts with real sex acts, and hopefully are able to re-educate yourself on what real sex is actually like.

In the case of #2, you deprive yourself of a completely natural pleasure.

I would put my bets behind quitting porn over stopping masturbation if the goal is to develop a healthy outlook on sex. I'd love to hear someone on the other side's thoughts though.