we make a hypothesis based on some time in the future. The Bitcoin account is one trillion. Assumption: 256 numbers or combinations of letters are 2 trillion (it can be calculated by mathematical formulas, here we make a hypothesis) Then: any modification of the letters in the private key, it will be the private key of an account .

It also applies to altcoins. But the number of Bitcoin accounts is the largest. It needs to make changes first.