"Why is Body Building so Over Complicated?"

It's only over complicated if you allow it to be. 

Be consistent, train hard, and try to add more reps/weight to your lifts over time. 

Make sure you're doing 1 exercise for each of the Big 6 movement patterns:

1. Squat

2. Hinge

3. Vertical push

4. Vertical pull

5. Horizontal push

6. Horizontal pull

If you're goal is body building, you'll also want to add in some isolations to ensure you're doing at least 1 exercise to directly target each of the main muscle groups in the body, (quads, hamstrings, back, chest, shoulders, calves, biceps, triceps, forearms).

Some necessary isolations, therefore, would include something for the biceps, triceps, and calves:

1. Bicep curls variation 

2. Tricep extension variation 

3. Calf Raise variation 

Optional extra isolation exercises might include the following:

1. Hamstring curls

2. Leg extensions 

3. Lateral raises

4. Rear delt flyes 

5. Hammer curls or some other forearm isolation exercise 

If you're keeping count, you basically have 9 exercise variations that you NEED to do for body building. You then can add whatever else you would like from there based on your own circumstances. But, even if you add several other isolations, you still might only need to do as many as 14 or 15 exercises during a given program. And progressing on those exercises is simple (mentioned at the beginning).

Oh – and do variations of exercises/lifts that work for YOU.

Gurus like to make simple things seem complex so you'll have no choice but to either give up or give them your life savings to inherit their wisdom.