Bridge weaknesses. Help me understand please.

So the hackers stole $600M from the bridge in Eth and USDC. I have so many questions…

1. How is it possible to drain funds from a bridge and why are these less secure ways of porting assets on the blockchain?

2. Surely that ‘stolen’ money can be tracked and eventually the hackers will be caught?

3. Is this punishable as a crime? Is this theft if the bridge had weaknesses that were exploited and hence the people doing so were expected to bear the risk of using the bridge?

I’m very unsure where the line is between crime and exploitation in the crypto space.