A warm welcome to the forums. I'm sorry to hear about what you're going through at the moment. It must've also been hard on you when a stranger on another forum commented that your behavior is of an "entitled child" when they do not know who you are exactly and what your current situation is like.
People have their reasons for being where they are at the moment. Taking yours as an example, you mentioned that you're "in no mental space and financial position to move out", plus you're happy currently and want to stay home with your mum while figuring yourself out.
On that line, people have other reasons for wanting to move out from their parents. Some want to be independent from their parents, some want to start a family of their own with their personal space. Moving out can be a very big step for a person, especially when they're purchasing a property because of huge financial decisions that comes with buying a property. So if you're not in a financial position to move out, then there's no need to move out so soon. It's best to have a plan and work on getting yourself ready for a move out, rather than hastily moving out without knowing how you will be supporting yourself when you do.
Now to answer your question on whether this is normal life to not move out these days. I don't think there's a norm in this. Everyone has their own wants and needs, and it is their choice on whether they want to move out or not. But there are advantages to be aiming for a move out and supporting yourself with living on your own. It sets you up so that you learn to become financially independent of your parents. Because eventually we will be put into a position where our parents can no longer support us. Also, moving out and purchasing your own property, is like working towards not becoming homeless. The money you invest in a house, will set you up to have a permanent roof over your head.
You might be wondering "I do have a permanent roof over my head at the moment, and it is my parent's home". That is true yes, and if your parents are okay with it, then that's alright too. But remember, our parents won't be there for us forever, and eventually we'll need to be able to live on our own. The sooner we can figure this out, the better it will be for us in our future.
I hope that helps, and happy to chat more with you uggaholic.