But it is useful for someone to make rules that are balanced and lead to interesting gameplay. There are entire companies that make their business around printing rule books and selling them to people who think it’s worth the money.
Think of it like this: if you have a high enough GM skill, then you’ll pass whatever check God has and make the game fun. But with more balanced and interesting rules, you get a bonus. Even if it’s just a +1 bonus that makes your game 5% more likely to be fun, that means everyone who plays that system gets that bonus from one person making it. You’d be crazy not to do it.
Different things work for different groups. But some things tend to work well in general, and others do not.
It’s impossible to make it perfect, but it’s trivial to make it better. For example, get rid of Silvery Barbs.
And we’d really hope with a large corporation behind it, they could do more than get rid of the obvious. They could do the playtesting necessary to properly balance martials vs casters.