Here is a fun article which recommends "quality over quantity":
https://www.psychologytoday.com/us/blog/psymon…really-have-sex?
And here is one on voluntary celibacy:
Is Voluntary Celibacy on the Rise?
How common is it for people to take a break from sex and dating? Why do so many people today seem to be doing it? And are they happy with their decision to…
www.psychologytoday.com
I personally would use the phrase "natural but unnecessary" (rather than "extravagant pleasure") and what falls into that category depends on the given situation - and every situation is unique depending on the circumstances - so I wouldn't assign sex as being "natural and unnecessary" all across the board. I would label something as unnecessary if only if it causes (or results in) pain or disturbance, or it is very difficult to aquire -- and this would reflect an Epicurean method of "choice and avoidance".