Sexual escapades are only senseless if you rigidly believe sex is only for specific things, and adopt a model where human beings are property and can be owned. While sex does have a biological purpose, that in itself doesn't mean it has to be limited to that purpose.
Sex is fun and most sex doesn't lead to procreation, nor is intended to. The last 50 times I've had sex, me and partner(s) involved have had no intention of making a baby, and that's fine. Nature/God agrees with me, because the number of children most families have are typically far less than the number of times the parents have had sex.
There's a lot of times people want sex and don't want it to be some big life changing event. I won't marry someone like that.
> This creates a mindset not unlike that of a drug user who is obsessed with getting another hit
Everyone wants pleasurable things with a minimum of bad or unwanted consequences. This is called being smart and using your God-given brain and free will. This doesn't make anyone a drug user. This puritanical war on pleasure can only serve authoritarian and anti-human ends, which is often an explicit or implicit base of forms of slavery/indenture, and is the main reason why I strongly advocate against it.
> The psychophysical reality of sexual intercourse is much more than some passing physical pleasure.
Anything that feels really good will beget attachment because you want more of it. When it's attached to a person, you're going to want to be around that person more. And of course, human beings are naked apes with courtship and bonding instincts and all that good stuff. But people bond over things other than sex, and any good relationship or marriage will have many bonds other than the sexual one. Indeed, marriages where sex is the only reason they got together are as hollow as this drug user strawman you trotted out.
> Masturbation is even worse.
People who become overly dependent on parasocial relationships with fictional anything, whether that's a harem, video game, movie star, person mentioned in a religious book, etc. need help. I masturbate from time to time and it does not give me any problems, but I'm not addicted to it. But I would rather lonely people masturbate themselves into a coma than sexually assault others simply because of people who will say masturbation is wrong but at the same time won't consider other things like legalizing prostitution.
> they don't want to make the cultural changes necessary to restore normalcy.
I don't. The old way sucked. Robots and AI should be doing all our menial work, and the possibilities for pleasure are endless. The people who just can't exist without an employer giving them meaning because they never got enough approval from their daddies need to move to another planet.