How exactly it's flawed or inadequate? It's still deemed secure until now and at that time, Satoshi couldn't use Schnorr Signature due to patent.
in the old days it would have been impossible. But now any password without a timestamp can be brute forced. Algorithms like Bcrypt are stronger. You can examine the range of timestamped ciphers with public hash used in cryptography.
And what exactly do you mean by lost wallets?
Before 2013, there was no movement. or wallets that were stolen and not moved, I have a 6-month research for these.
73,000 BTC lost wallet and 155,000 BTC Lost and Stolen wallet total.
Personally i find it's hard to believe SHA-256 collusion happen that easily.
there are many privatkey sites. But none of the methods, none of them are the same as the structure I created.