Just my two cents--I might have thought this once, because once I had ok sex, and since then Ive had incredibly amazing sex.
For me, as a woman, I think it all comes from learning, being more confident, and knowing my body.
AND being with partners who truly love sex on every level and are willing to push boundaries, go the extra mile to please me, and me being very open and aggressive as well.
I do think the more two people can open up to sex and just honestly enjoy it--and tease each other with it all the time--the better it can get. In my case sex has gone far beyond my expectations when I was younger and I expect it to continue to do so.
So how is that for some optimistic thinking??
PS, As Ludacris (a famous rapper) would say, "Some say that sex is overrated, but they just ain't doin it right!"