if there is an actual "cryptocurrency hack" then there is nothing you can do to solve it. the project is broken and will be dead. as it has happened a couple of times in the past with some altcoins that died because they were flawed.
but if you are talking about the "hacks" such as exchange hacks, you getting your hot wallet hacked,... then it is the person's fault not the system and you can't solve that issue with an application!
for example when people keep their bitcoins in a hot wallet on their desktop without any passwords and they download viruses, an "app" can not fix it! they should have thought ahead and used cold storage in first place.
This person is right, if a cryptocurrency is hacked, then the coin dies and it will certainly not be able to live again
but if the wallet exchanger is hacked, then it is purely an error from the exchanger who is unable to properly secure the user's funds
yeah, i agree with your opinion,
if there is hacking in an exchange it is purely an exchange error that cannot secure the assets of their users.
it is very difficult to solve the exchange hacking solution, because no matter how sophisticated the exchange technology is. if the exchange does just a little mistake the hacker will take the opportunity to drain the assets that are in it.