I did not run a rear sway bar on my TJ for 8 years. It was in the way of my triangulated 4-link setup.
However, as eluded to above, the front sway bar does more work to prevent a roll over than the rear does so you could argue that it’s the more important of the two. The rear is less stout and provides less resistance than the front. However, that also means that it does not provide a ton of resistance while you are off-road. Meaning it’s not really limiting your flex or droop very much. Given that it’s not really hurting you off road, and it’s keeping the rig stable on road, what’s the point in losing it?
I will say that there are some benefits to at least some anti-sway resistance when you get off-camper while off-road. They can prevent rollovers off of the pavement as well.