Before I was a sex educator I was a celebrity personal trainer for 15 years. Just like you don’t want to put effort in at the gym with no gains, there are many times in sex when you want to provide the maximum amount of pleasure for the least amount of effort. Sex pillows optimize biomechanics, so you can get the job done more precisely with less effort, and give you the option of altering the sex position you’re in so that it’s optimal for both partners. – Kenneth Play
See my recommendations for best sex pillows in the article The 7 Best Sex Pillows You Can Buy, According to Experts by Zachary Zane for Men’s Health