Is the side stuff worth?

I have tried to give this game a chance like 6 times already and never clicks with me. I have come to released the reason I drop it is because I get burned out by all the optional stuff the game throws at you.

I'm a completitionst player, I always try to do the closest to a 100% in any single player game, but man, I'm on hour 8 of my most recent attempt (right after you are sent to Port Knot) and I've already been back and forth to the first checkpoints for the fourth time or so, Wind Farm, Abandoned Factory, Distribution Center, Capital, the same points over and over again.

Should I just focus on doing the main story?