See statements like “Dont use it all the time, but do sometimes and THINK it’s better”
And all of nothing statements like “Firm believer ALL trailers need sway control.” is why or where folks get wrapped around the spokes with this.
GDE just put it well.
And similarly there are certainly many setups that need one or both, and many that don’t. And it’s ok to express your preference for “perfecting” your ride unless you pretend that it’s a necessity (in situations where it isn’t).
The fact remains though, many wdh and sway setups are purchased purely through salesmanship by RV salesmen and the internet. And many others are purchased out of fear of the unknown by those who don’t know better.
But many of those same people can’t see past defending their purchase or personal preference by refuting anyone who suggests otherwise.