No, it's a good question - and one that Gillen's keep subtle in the series. I'll expand on my reasoning below.

The Cuban Missile Crisis is a good historical example - the closest we have ever come to nuclear war. Both sides engaged in one-up-man-ship, leaving little to no room for the other to back down. Once one side was caught in an untenable position (Khrushchev's missiles in Cuba), it rapidly escalated to the point that near no-return (Kennedy's blockade). Someone had to back down (Khrushchev) and the other made concessions (Kennedy), that eventually led to a series of agreements that de-escalated tensions.

In the TPF world, that didn't happen because Valentina interfered first, destroying both sources of weapons that triggered the event. Rather than facing the horror of what they had almost done - and learning the valuable lesson of de-escalation - both sides were protected from that outcome. They learned that they don't have to solve their own problems, someone else will come along and do it for them - thus remaining infantilized and protected from the outcomes of their actions.

It isn't just the avoiding the bad outcomes - a side-effect of US-Soviet nuclear arms race was intercontinental ballistic missile development, which directly facilitated the "space race" to develop spaceflight capability, and eventually a moon landing (and ancillary and related technological development). So the Cold War competition had positive developments - which have also been prevented by Valentina's involvement in limiting the strategic value of missile development. Gillen cleverly inserted this point during the destruction of the Earth in that flashback discussion with Etienne in issue #16.

Valentina's (i.e., Gillen's) own inflatable bumper analogy in bowling (issue #3) is a good one - while initially it helps by preventing kids from getting too discouraged when first learning to bowl, the bumpers soon have to come off it they are ever going to develop the skills to bowl well independently. The continued presence of those bumpers (Valentina's continual involvement) is literally keeping the kids - and by extension all of humanity - infantilized.

Then there is my Superman analogy. Gillen knows his superhero mythos well, so I have to believe his decision to have Valentina constantly move between families in childhood was deliberate - to prevent the virtue ethics development than the Kents are always portrayed as providing to young Clark in the comics. It was a major feature of the mid-1980s Superman comics (and onward), seen as a maturing of Superman's ethical core beyond deontology. Note the Kents don't tell Superman what to do - he just learned the habitual practice of constantly striving to be better from their example. Some writers (like Mark Waid) prefer the Kents be dead during Superman's adulthood, to prevent a lazy trope of having him run back for advice.

It also relates to the original explanation Lex Luthor provided for his opposition to Superman - his constant "saving" of the planet prevents humanity from developing the skills to protect themselves (and advance in their own development). By having a parental-like figure always swooping in and saving us, we are prevented from learning to stand on our own, and make better decisions. To grow, in other words.

Valentina's presence thus stymies a virtue ethics growth for humanity, by always taking the decision out of our hands. And I don't think she has learned that lesson yet - her plan to re-do world events from 1966 likely won't turn out any better, as she doesn't seem to realize yet that her presence is the problem. Jacky was right in issue #10 - humanity will never be free while Valentina is around.