Is sex with a large penis really this much better?

It feels surreal that I’m asking this, but I’m fwb with this person with a 9” penis. I was so curious, we actually measured it. It’s as thick as my forearm. The first time we had sex, was one of the best experiences of my life. I’ve only been with my ex girlfriend of ~2 years. The feeling of 9” forearm is so much better than any sex my ex and i had. now im confused as to what my sexual needs are? big dick sex has been amazing, and id like to ask if this is mainly because of it being so big? i’m not sure if the physical pleasure is supposed to feel this good just cuz the size?