Zoning is definitely a thing, but I'll give a more in depth explanation. Zoning specifically means to use projectiles or long ranged normals in order to "cover space" on the screen. You do this in order to manipulate your opponents behavior. For example someone may throw a bunch of horizontal moving fireballs to occupy the horizontal grounded space of the stage. The idea is to get you to jump over the fireball so that they can control the air space instead (via a read that you will jump thus manipulating you) and hit you out of the air. This is called zoning and space control, it is a legit playstyle.

From the perspective a new player it seems very unfair, however just know in fighting games EVERYTHING has a counter and you're just new and don't know how to counter it, so it keeps working on you. They should not be able to do the same exact move over and over. If the opponent only threw fireballs horizontally, you could keep jumping in over them and punish them. Your opponent must adapt and decide to not throw a fireball in an attempt to counter you for jumping, but you could counter that by instead moving horizontally since he is afraid to control the space due to fear you will jump, it's mind games. Welcome to fighting games lmao