I too have towed TTs for decades. Never really needed sway control.
But then there was an incident in I55 in Mississippi. A really nasty looking storm approaching from the East. We crested a hill where the trees were clear cut on both sides of the road. We got side swiped by a huge gust of wind. It blew my 36' trailer towed by my Ram 2500 hard to the right; then the trailer bounced back left. NO ONE can tell me the sway bars didn't buy me enough time to reach down to hit the trailer brakes to jerk it back in line. Do what you want, be cheap, macho or whatever, but they are cheap safety devices. I also have never used my safety chains for their intended purpose.