So, i think that the confirmation bias is really a problema here. One sentence i like to use to summ this problem is say: Hey, OK, but what about all those attacks at 30%, or even 18% chance to hit wich actually did hit?
That said, i understand (damn, i REALLY understand) the frustration – especially when it causes a important loss.
I know a game called Hard West wich uses a “luck” mechanic. Every character has a luck amount. Your hit chance usually depletes the enemies luck until it zeroes and then you hit… Sometimes you seem to able to hit without zero the enemy luck, i don’t understand exactly how, but it’s something to think about.
That said, i like the rng element. It’s frustrating at times, but sometimes that is good. Keeps me on my toes during fights. I know i have to pull back someone that was hit even if i think he can resist a whyle, because, after all, you never know…