Who benefits from steroids more....?

Pitchers. They are continuously tearing their arms and one of the main pros of using steroids is improving healing time and stamina. It may help hitters knock a few more out of the park but they don't even make contact 100% of the time. It would help pitchers every time they hurl the ball.

It helps the batter more. Steroids do increase the velocity of a pitch, but pitching is about location and movement, neither of which would be influenced. Batting with steroids still requires timing and accurate movements, but the bat moves quicker, allowing for more power.

The hitters, swinging a bat can be enhanced by strength. Pitching is more a motion of phyics, so steriods don't help quite as much with pitching speed.

pitchers, it helps them be able to pitch longer, and more often

not the player's wives..... the hitters because they get more power

The guy who sells it to them!

neither they both end up hurting or killing themseves

braber has it exactly right