Why do special moves in fighting games require complex button combinations?

I recently started playing Guilty Gear, and it's made me frustrated for this reason.

I still intend to practice and get the combos down, but I can't help but ask why such a thing is necessary.

Each character has a unique arsenal of special moves, but how is the game improved by locking those abilities behind difficult timing challenges? Surely this artificially raises the skill requirement, and has you practicing the same moves over and over, rather than being able to focus on practicing strategy.

My main competitive game is Overwatch, and I just can't imagine the frustration if I had to worry about failing to activate my abilities, on top of having to worry about using them correctly.

It just seems so unnecessary, why does this happen from a design standpoint? What does it add to the game? What do you think about it? Would these games be better/more popular without this sort of design?

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Edit:

I will now address some of the important points people have made.

I've learned two important things to start:

First, Guilty Gear is a particularly hard game

Second, Venom, the only character I have attempted to learn, is possibly the hardest character in that game.

Despite this fact, I still want to play this character and game a lot. I have had fun with it so far, and I am too stubborn to give it up, or to play on "stylish", or to even choose an easier character when this one is so aesthetically fantastic.

I also want to emphasize that point:

I am having fun. I love the design of Guilty Gear and am not deterred from playing it.

A lot of commenters seem to be under the impression that I am whining. My post isn't about the game being too hard. I am not saying I can't or won't learn. I am not saying the game needs to go back to the old Street Fighter that had only one moveset and no fireballs or anything.

The barrier to entry isn't insurmountable. I am simply frustrated because it doesn't seem necessary. It seems like the execution could be made simpler and open up the strategic and competitive gameplay to more people who would maybe have not enjoyed it before.

And that's helpful, because something that is actually much more frustrating to me is the lack of an online playerbase for this game. A wider audience would mean more robust pools of players, both professionally and in online matches.

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For the most part, I've gotten good answers. I agree that the current way of doing things creates a feeling of accomplishment, and adds an intense satisfaction to landing moves under pressure. And I will enjoy learning this game and becoming better.

So I'll reiterate, I'm not a kid complaining that my hard game is hard, and saying it should change to make me feel special and included.

I just think it's important to question things, and I think a bit more accessibility may be a healthy thing for these games.