If you say 10% is probably not much, then why would it suddenly "Add challenge", also how does getting materia and putting it on your gear "add challenge", that is not a challenge, it is easy.

Also due to AF system, you cant add materia to those pieces, nor can you add them to jewels, so where exactly would the Materia go?

I believe that while you're throwing out a nice suggestion, you're not ultimately thinking how it would be used and how much loopholes it has, this is likely why you get such trollish replies because you're not thinking about everything affected. You just see it as a "buff that makes things easier" and think that by removing that buff, everything will spontaneously go harder.

Not to mention that buff is helping a lot in some of the bigger fights, and very much promotes people to full party.