I'm far from technical but from what I read somewhere in the (near) future quantum computers will be a thing and their capabilities will keep on increasing. So per definition it will become a threat sooner or later to crypto.

I also read Bitcoin protocol will be updated to protect it from these attacks. How would that conceptually be possible ? The only solution imo would be to make the private key more complex ? Would be impossible no ?

Again not technical and only using my basic knowledge so don't attack me