The demand for child sex is fueled by porn & fornication which in turn comes from decoupling sex from procreation, marriage, and family.
Ultimately, this has its source in idolatry and the rejection of God.
We're being shown in real-time the logical progression of liberalism. Rejection of Jesus -> Rejection of external divine authority and law -> acceptance of internal authority and do whatever I want -> acceptance of birth control -> sex is for fun -> acceptance of divorce -> acceptance of baby murder -> acceptance of child sex etc. etc. etc.
This idea is not supported by scripture in the slightest. There is the commandment for Adam and Eve (and the descendants of Noah) to be fruitful and multiply, but that does not imply anything about the relative importance of pleasure in sexual intimacy. You are reading into the Bible something that isn't there.
Then explain Song of Solomon. Children are hardly mentioned, if at all. Yes, it can be used as a metaphor, but the metaphor doesn't make sense unless the physical or literal aspect is at least somewhat true.
Also explain Hebrews 13:4, "Marriage is honorable in all, and the bed undefiled: but whore mongers and adulterers God will judge." No children mentioned there either.
It is not the focus on pleasure that is the problem. It is the obsession and idolization of it. The problem is not the pleasure, it is man's tendency to reject God's boundaries regarding how the pleasure is derived.
God created some things, like food and sex, that are inherently pleasurable when they didn't really have to be. He created them that way because He wants us to have good things and enjoy them, again according to His design (which actually makes these things the most enjoyable without the guilt and consequences of sin). The fact that Satan and our sin nature twist these desires into something abominable, doesn't render the original pleasure itself sinful or "lesser".
Right there.
Onan is having sex, not for babies, but for pleasure, and God sees it as wicked and strikes him dead. And before you give the common argument that God is punishing Onan for not fulfilling his duty to bear kids for his brother, here is the actual punishment for that:
Notice that the punishment is not death but humiliation.
Here is Martin Luther:
Yes, Oman was intentionally not trying to have children, but that doesn’t mean he was doing it only for pleasure. You’re setting up a false dichotomy.
He was doing the bare minimum to make it look like he was doing his job, without actually doing it. As for why he was struck dead when the usual punishment is humiliation, note that he was supposed to be an ancestor of Christ. He was “preventing” (humanly speaking) the advent of Christ through the line of Judah. That’s why God killed him, so that someone else would actually do their job and continue the line (even though that eventually came through Judah’s own sin).
I see you have to quote other people’s opinions of scripture, not scripture itself, to derive your perception of human sexuality.
The only person you are quoting is yourself.