Complexity in ESports

I've noticed a trend in esport games, that simple balance seems to be almost forbidden in the development community. To me, it's nice yet frustrating at the same time. One day I like to learn about all the thought that is put into the decisions made by developers, and the next day I wonder why defense and attack can't be scaled equally, instead of getting nerfed one update and buffed the next.

One of my values in the games industry is user-generated content/sandbox features, to the point of being able to submit stories, art, gameplay levels, champions, etc. This provides endless content, and developers can just sit back and monitor everything. I often think that with equal balance, or an entire system that is balanced at its core, and everything in a game is governed by that system, users would be able to make their own skills/items/champions without worrying about balance, because the system would automatically calculate for them.

For example, when creating items and champions, each variable would be measured and rated, and a champion/item would have its share of total rating. For example, out of a pool of 300 points, Azir's passive could be 40 points, and his Q could be worth 80 points, etc. Factors such as cooldown, AP scaling, duration and base damage would be measured. For an item, 1 Health could be equal to 2.5 Gold, and a crafted item out of a total of 4000 gold, you could make a starter item for 375 Gold that provides 150 Health (judging by Ruby Crystal, Riot calculates base Health passives to be at a 1:2.66 ratio). With a 1:2.5 ratio, you can upgrade your health item to a secondary item (Firegem for this example), which is a 450 gold difference. 50 more health would be worth 125 gold, so the 10% cooldown unique passive would be worth 325 gold.

I am not sure if all of the items are measured this way, but sometimes I wish this was the way items were made.

I also often thought, growing up as a teenager, that I could make a game that follows these values, and expect games in the MOBA and MMORPG genres to be supported through content monetization of the creators, and everything would be balanced from day one, with little amount of maintenance required (tactics change overtime, and exploits would be dealt with). You could have a game with a market like Second Life and IMVU, and content creators could make real money with royalties going to the game developers and any copyright.

Of course, I must be missing something. Now, I'm doubting if the ideas I come up with when pacing in my bedroom are worth becoming a developer for. I feel like if I ever put up a system that used similar algorithms for attack, defense, magic and ranged, that it would be the first to be rejected. Perhaps I should stick to alternate careers and don't bother getting too serious with games.

I have three questions for everybody: Why do games have to be so complicated? And why do game developers seem to favour complicated features? Or do you think that the balance usually starts off healthy, but as the game becomes more complex it becomes harder to maintain?