If you're hitting fatigue every day fishing, you're either botting or wasting way too much time with it. When I actually tried to cap that because stupidly large number of GP fish for the day it took me over 3 hours, not sure how many exactly because I have to take breaks from that trash.
Chocobo digging, i can hit fatigue in <15 minutes, it really is far too low. Generally can't even get a full stack of the good items. (HMP is 0~2 from what I've seen in months of digging)