Yes, absolutely. I agreed with the parent too, but I think your explanation is not as different as it seems. I think your framing is just more direct and correct.

However, one big caveat:

"If you want a secured dignified life and basic prerequisites to starting a family"

What you're saying is more relevant to the state of already-developed nations, that are now all in a slow decline. Not so much to newly developed nations, slowly on the rise.

That context established:

The common "we can't afford children" explanation is certainly a significant part of the equation, but I have never bought that it is the biggest reason. Children are expensive, but highly subsidized, and just not expensive enough to explain the whole picture. Your explanation is, I think, the One Big Thing. So many adults today grew up seeing middle-class life as very attainable with a college education and a work ethic. Then, as they became adults, that "attainable" reality inched away as fast as they progressed toward that goal.

The big, tough thing to discuss (tough because of the modern obsession with attacking "entitlement"), is that humans react much more strongly to change in state than to the state itself. E.g. if Alice grows up in a local culture where most people are poor, and Bob grows up in a local culture where most people have little houses and little yards and low crime, and then Alice and Bob both end up poor, then Bob is a lot angrier than Alice. Bob shakes his fist at the world more, and is more likely than Alice to choose to delay having children until he attains what he thought was a totally reasonable American aspiration.

This is highly parallel to the parent's notion of "not having children in order to pursue other things". It's not just that people don't want children - it's that they want children and middle-class lives, and feel uneasy choosing children when it feels like one more bump on the path to a middle-class life.

Well put. Adding that for those who are looking to have kids, there are generational considerations. It's not only the parents wanting the middle-class life for themselves, but it's also understanding that raising a child with that level of access to resources is what ideally sets the child up for a better life onward. The impact is exponential down the line, and no one wants to be responsible for a move in the opposite direction generationally.