The observable universe isn't a black hole, and we're pretty confident of it, people keep making this observation every few years. There are some interesting analogies between our universe and a black hole, but they're mostly just general concepts that occur all over the place.

For example, we can create little analogue black and white holes in optical fibres, they even have the same horizons and similar governing equations, but they're still not black/white holes. You can honestly get the same effect by just being a bad swimmer and getting in a fast moving river.