I know that in mathematical terms, finding a private key of a bitcoin address is virtually impossible ... but not impossible.

Having said that, a site like https://www.privatekeys.directory/ gives the ability to virtually explore all the private keys existing in the elliptic curve. The Random button on the site https://www.privatekeys.directory generates pages of private keys that could reveal addresses with a positive balance!!!

Considering that whale accounts and exchange accounts contain thousands of bitcoins, one lucky guy could accidentally find millions of dollars on hand !!

From what I understand the only defense against this event is to divide your assets into many accounts to reduce the risk. But even this trick can't ensure your funds aren't stolen by a lucky dude.