How to insulate exterior walls with electrical wiring
That's... artsy-looking wiring. I believe the stapling or lack thereof doesn't meet code. We should give due credit though for not jamming all those cables through as few holes as possible.

In any case, you asked about installing fiberglass insulation around the wiring. In the case of cables that fit neat and tidy against a wall stud, as do the three white and one yellow starting at the top left, simply install the batts and don't worry about it.

Cut away insulation so that it fits neatly around junction boxes.

Where cables pass through the middle of the depth of a bay separate the batt halfway through its thickness. Slide part of it behind the wiring and lay the other part in front. This minimizes the compression of the batt. It would also be possible to make cuts in the batt so that the batt can expand around the cable, but if you're using faced insulation it's best to avoid cutting the facing.