Our Universe appears to be expanding and cooling, having originated some 13.8 billion years ago in a hot Big Bang. However, it's plausible that what we see from inside our Universe is simply the result of being inside a black hole that formed from some parent Universe. If the black holes that form in our cosmos give birth to baby Universes, perhaps we arose from the formation of a black hole ourselves.
Anton Petrov just put out a video with a similar topic: https://youtu.be/l4C6Ll6sIQU?si=ac9K5RKYrbFmyapj
He is an awesome science youtuber and does a great job of explaining research on these kinds of topics.
I haven't watched it yet but will soon. (It popped up on my feed today and remembered it, just for you!)
I really like his content, but his way of speaking (can't even say what exactly) is somehow perfect for my brain to completely tune out. I have to really focus on it to actually mentally process it.