No IT system is perfectly secure. None. They can and will be hacked. The point is to raise the bar for that hack. You lock your house, your phone, put passwords on account, etc. even if they can all be broken into. Why do you do that?

You still haven’t mentioned the method you find acceptable. Even what I suggested originally (distributed hashes) can be bypassed. A determined attacker will impersonate the author, will take over the blockchain, will replace enough instances of the hash in the wild to make it look legit, etc. so you complicated everything without guaranteeing anything.

If you indeed support the idea that the cert/signature system is not perfect so it’s useless I’m sure you can mention one that offers guarantees. You’re arguing for the sake of arguing but brought no argument you can support. Have at it.