At the moment I can't vouch for any exchange to be safe even if there are any. It's too risky leaving your funds in exchanges but I do believe in future exchanges would be trusted and they would keep people's coins safe. I do not know when, I do not know if it would even be in this life time but I believe it will happen.
Take the banks for example, they first started like this. Going insolvent and losing people's money. As time went on they evolved and things change. In today's world I've never heard of somebody that lost his money because the bank crashed or was hacked. Regulations have been made to prevent things like this from happen and the customer interest have also been protected should anything happening.

I believe this is the beginning stage of crypto exchanges. These are the baby steps. These are the things that happen that make them learn and evolve and become better. It's how the history and evolution of man works. So I really believe if crypto doesn't die in future (which I know it won't) exchanges would play a big part in it.