Humanity has developed a rather peculiar approach towards sex. On one hand we have the automated need to procreate and from the other the cultural context upon which the act gains meaning. The majority of humans claim to be different from other animals yet again we have create a meme out of the most simple of all acts.
Whether we like it or not, everything is connected to procreation. Being our primary biological function, everything else our species has build depends on it. The main reason for this is the structure of our brains. Our higher functions that stem from the neocortex are directly depended on the more primitive limbic brain which is too connected to the reptilian one. Our instincts that step from the reptilian brain are identical to those of the other animals. Our limbic brain then takes those instincts and decodes them into emotions. This part is also shared from many mammals. What makes humans slightly different is the extra step of decoding that filters through the neocortex. This is where our primitive instincts such as the one of sexual desire get a new narrative.
The narrative might be as elaborate and diachronic as the one religion or as parodic and withering as fashion. Nonetheless the part that everybody comes together is the one of pleasure. It feels good to engage in the act and for many reasons. A religious person might feel good for fulfilling their spiritual part as a higher being. A hedonist might just do it because they feel good. A sheeple might do it because others are doing it.
Over the last half a century or so, I believe most of the developed world has adopted the sheeple perception towards sex. Muscularity has only recently emerged and gyms have become a thing only over the past few decades. Billboard and tv ads are showering us constantly with images of sex and pleasure. Much like the new iphone or the new video game, we have to get it in order to feel good. If it's advertised after all, it means that everyone is doing it — or at least craving for it.
Humans have also a rather interesting way in forcing their views toward the minority. If the vast majority of people have families and it is regarded as a socially distinguished act, then it becomes a necessity for the rest to adopt the trend. In much the same way, if something becomes fashion then everyone tries to imitate that behaviour. If an individual decides to opt out then they become isolated. This is why even suggesting that sex is overrated might be looked down upon. Everything that we have been taught about sex reinforces the idea that it is very important whether one decides to have it for fun or to procreate.
Pleasure is a rather peculiar concept as well. Many things can make us feel good and if we overdo something then the reward ratio begins to diminish. This is why the more we have sex with one person the more bored we get. Nature has programmed us to have genetic variation aka have sex with as many different people as possible in order to create more robust offspring. Monogamous relationships are only a recent cultural invention and as the ratio of divorces suggest — not a very successful one. Love is also a very recent invention. People in the past had marriage for business reasons. Love was considered an immature tendency that teenagers had. They understood how ephemeral the whole process was and thus they kept their distance from risking the entire lives towards it.
The only reason we have love and sex advertised so much today is because of marketing. Contrary to common belief, sex doesn't sell. Sex is sold in a market that is conquered my FOMO (Fear of Missing Out). We have to have sex before we get to old. We have to procreate before we get too old. We have to tend to faces and bodies in order to have sex because eventually we won't be able to do so.
If sex was a universal and timeless idea, then billboards and tv ads would include equal amounts of 60 and 20 year old models. Instead we see sex being connected with youth, strength, power and dominance. Whether one wants to be romantic or not this is raw social Darwinism. The pretty, young, healthy and powerful will procreate and prevail over the rest. Thus, we have created an idea of sex that everything is directly linked to it. We want a good career in order to create a family aka products of sex. Some just want to make bank in order to have as many women as they wish. Without realising it all that can pleasurable in life is linked to sex because others have already created a narrative around it.

In the near future sex will be easily substituted from a VR set and some cables. Your primitive brain will be able to get all the direct stimulation based on a narrative that resembles a game that has increasing difficulties. Much the same way, most children today don't find playing sports that fun sex can easily be substituted from technology that offers it much safer and with much less stress and unwanted consequences. Sex will remain in history as a primitive act of a species that got confused about pleasure and procreation.
Ask yourself: If you had the chance to artificially simulate the sexual experience identically to the real thing — while at the same time ensuring that you could clone yourself — how much that would affect your current perception about sex, family and procreation?