Yes, all females have a clitoris of some sort -- developed to various degrees in different women. As is true of the rest of that area. And the extent of development depends principally on the extent and timing of testosterone stimulaton.
A clitoris is certainly not essential to reproduction. Nor are the paraurethral glands/female prostate. The comparable organs in the male are essential to reproduction.
I fully agree that they're valuable in the female and I agree that for females sex does tend to get better the older we get and the more, as a result of increasing age, testosterone tends to predominate in our hormonal balance.
The more testosterone predominates in our hormonal balance, the more we're likely to come to cllmax easily and indeed one of the obvious indicators of high levels of testosterone is a larger clitoris.
cllmax is a response which demands a certain level of "male" hormones to come about. Many, but not all women, have a sufficient level for it to be possible. Some women have sufficient male hormones to cllmax very easily.
It's just a pity more guys don't realize that it's the most masculine girls who cllmax most easily.