When it comes to designing mechanics, there's an interesting difference between a good designer and a bad designer and I think it ultimately comes down to intuition. Ultimately, when it comes to mechanics, the designers job is to ensure that they'll tweak parameters in a way that 'feels just right'. And not just to them, but to the wide audience that'll play the game. I have found that to be an extremely rare skill amongst designers and this skill doesn't seem to scale much with experience. Meaning, I worked with designers that only worked on one or two smaller titles before that were able to nail it. At the same time, I worked with senior designers with decades of experience that were utterly useless at that job and were never able to get the tuning just right. I saw a similar phenomenon with musicians. Some musicians have an inherent feel for harmony, melody, etc., whereas other musicians even with decades of experiences will never be able to quite nail that aspect. This might be really disheartening for some people to hear, but apparently there's even some science behind this phenomenon: