Sometimes certain things are also revealed to me in my dreams or visions (and very, very detailed). So, I know this is possible.
I don't know why "God" does this. At least it's a good reminder to not waste my time, because we never know when death knocks on our door.
Quite a few of these visions happened in reality, so when I get scary ones about the future, they do make me think twice.
Sometimes they are handy too. There was a criminal who stole from many people, and also 100 dollars from me in India. And one day (1 year later) I got a vision, that this man came to my village again, I did not take it serious, and was too surprised (and scared) to act on it when it happened next day. So, he got away with it. Next year another vision. Again, I let it go. And the third time I had a vision, I was having my beard shaved at the barber, when the criminal walked by. Next day it happened exactly like this in reality. I ran out, got hold of him, and did not let him go, until he paid me the 100 dollars back.
God is good, after 3 years I got my 100 dollars back. And the lesson I had to learn was to become MUCH more assertive. That was what it was all about IMO.
So, God gives me those visions to help me, to show me, where I need to learn things. I am a slow learner (not listen to it twice). But, now I do take the visions much more serious. Other people who dismiss them as nonsense, don't know what they talk about. Obviously never had this type of experiences.
IMO: It's always good to ask "God" why He shows you the visions. Sometimes my visions have quite different lessons than I thought in the beginning.