The exchange or other centralized system don't have the facilities to prevent scammers or hacker's from gaining access to your Bitcoin.
You have it backwards. Good, established and large players have extremely sophisticated systems to prevent unauthorized access, but individuals have no such facility at all.
Individuals have lost billions of dollars trying to hold on to their own Bitcoin.
I support and encourage people to store bitcoin themselves and not rely too much on centralized platforms but I also disagree with many people who are badmouthing centralized platforms or governments. Obviously they have much better security and safety systems than individuals, they can not only detect and prevent attacks in time but also make hackers pay the price. If this is a personal wallet attack, don't expect the hackers to return our money but the government can do that.
Also, we like to criticize and badmouth centralized exchanges or government but we end up using their services to sell or buy bitcoins. I want to ask, is there anyone here who has never used a centralized exchange or does not have a bank account? If we are still using and depending on them, please don't speak ill of them because that doesn't make us any more beautiful.