>>1005204The arm is made of a chain of bones, they all have copy rotation constraints targeting the hand bone, but with lower influence as you move further away from the hand.
you can duplicate and subdivide your main deformation forearm bone, then lock every group in weight paint mode except for the forearm and the new bones. then you can easily transfer the weight from the old bone to the new ones with auto normalize. then just smooth them out as needed. then set up the constraints and you're all set. for this rig you could probably get away with just 2 bones, the one I showed you has 4-5 i think.
rigging is difficult but rewarding, why do you think so many people just use auto riggers? but if you gitgud you can make rigs that are so much better than anyone else, with or without auto riggers.