Maybe you are not doing your own research? There is plenty of information to support a Brexit if you can be bothered to search for it but ultimately it comes down to your political leanings and whether you are a person that likes to feel secure with an autocracy directing things.
The problem I'm seeing is that most people are confused and basically lazy or haven't got the time or the inclination to sort it out for themselves and want to be told how to think. I include myself to a degree in that. I am beginning to recognise that the heart of the issue is with the Common Agricultural Policy because that is where most of the money goes but that is a complicated field in itself. The group that have their eye in are the farmers as they are at the sharp end of the CAP so their opinions and arguments are worth noting. At the moment their forum is in favour of leaving by a good margin. The Government propaganda machine doesn't want to go there (CAP) because it could reflect very badly on staying in. They would rather you remain ignorant of how our money is dished out, to whom, where and for what. The farmers themselves are trying to see through the smoke that clouds any clear vision of EU (agricultural) finance. I could write reams on it but I'd rather leave it to the farmers to argue the toss.
The reality is that there are no clear cut assurances for a secure future whether we stay or go. It will probably come down to a visceral decision in the end. How the nation feels in its gut.