My neighbours are notorious swingers. I often sit in the garden late on a weekend night, listening to the shennanigans (they have a hot tub & 'party' area in the back garden). Each to their own - they certainly seem to have a good time.
I think you need to be a certain sort of person to be a swinger. If you're a jealous sort, it wouldn't work. I think the danger of it is that one partner 'falls' for a swappee and wants to take it further than the odd dalliance.
My neighbours wife didn't want to try it initially, but her husband gave her an ultimatum - join in & the marriage is over. I'd have told him to go to hell, but she said yes & now enjoys the whole scene as much as, if not more, than him !!
Personally, I couldn't go for it.