Strange idea. What do you compare here?
The JWST showed us that it is and was a mature, i.e. adult, universe from the beginning.
What is an infant planet? Nobody teaches that one planet is an infant, i.e. just born, but that is the assumption with the Big Bang, That universal bodies just come into existence. We observe nothing of the sort and now we know that was the case in the past. Remember, we thought that we had an infinite universe before. We see there is expansion of the universe or galaxies moving away from each other and collisions, but no new galaxies nor new bodies.
... I do not think you try to understand what you speak about on your own. Mass for example expands time. So in a black hole for example could exists no time at all but an infinite space. This someone is able to say with some plausiblity although we are not able to know what's going on in a black hole - if there is going on something at all. But a black hole is 100% universe - the whole energy of a black hole is here in our universe. But what to say about the universe? The sum of all energy of the universe seems to be 0. So if you could be outside of the universe (although it exists not any outside of the universe) and you could take a look at the universe then it would not exist. There is no energy. So in fantasy could be in every point all around you an endless number of universes. But such an idea is without any scientific plausibility - it shows only how we are able to think.
I'm not arguing against the universe expanding and spacetime. However, one has to ask where the energy to do this came from? We know we can't just create energy, but it can only be converted.
Moreover, it's the black hole that is the death of planetary bodies as it seems to destroy matter. We also see collisions of bodies through our telescopes, so the destruction of matter is part of our universe. No birth as such claimed with the Big Bang. Is that what you think/observe with the black holes? You can think that, but have no evidence for it.
From which point of view "vast"? And why and how do we know that our natural laws here are all over the universe the same natural laws? We never saw any exception of this rule - that's all - and that's why we call such rules "true".
It's Hubble's Law which deals with the expansion of the universe, but not its beginning. If there was a beginning or even a Big Bang, then there had to be creation of energy which is impossible.
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Masses bow the spacetime. So planets fly always on a straight line around their central star. But this balance is not perfect. The moon for example leaves the Earth - but Phobos will collide with his planet Mars.
Again, the death of universal bodies. No new creation even from black holes.
