However, you still need to calculate the checksum, so will need to input your entropy in to some software since you cannot do that by hand, and you will still need to turn the resulting 132 bit number in to a seed phrase, which is prone to error if you are doing it manually, and you will still need to import that seed phrase in to some wallet software to generate private keys and addresses.
You needed to do these before too. What you ensure is that your random number generator doesn't take part into the procedure of wallet's generation, which is kind of significant if you understand that there's no way to truly confirm it returns you random numbers. The other activities can be confirmed if someone wanted to rip you off.
Time to be completely pedantic, but actually it's around 1 in 2121, rather than 1 in 2128.
Yeah, I forgot to say this. I included the possibility for someone to have just generate their wallet without the checksum verification. Almost all wallets do that, but I included they could have done it manually.
Not that any of that matters. They are equally impossible.
Yep, they're
very large numbers.
@Zedpastin, no one is ever going to steal your money by brute forcing.