I’m not sure this is universally the case. I’ve dated a man who was like this, and it produced two things:

1. The relationship itself became less comfortable. I wasn’t always free to be who I was because I was trying to put on a show all the time.
2. The sex, while adequate, was not always that great. It felt like the same hookup over and over again; exciting the first few times, but after a while, a little boring and lacking in intimacy.

However, I’m not great at relationships, so maybe don’t take my advice, haha