The additional words in a 24 word seed significantly increase the number of possible combinations, making it more resistant to brute-force attacks.
Both 12 and 24 word seed phrases are impossible to brute force from scratch. How impossible they are is irrelevant.
Both the 12 word or 24 word seed phrases generated by reputable wallets typically provide 128 bits of entropy, making them equally secure from a cryptographic standpoint.
24 word seed phrases provide 256 bits of entropy. They both provide 128 bits of
security.
12 seeds is enough in my opinion, it's 132 bits of entropy:
Only for Electrum seed phrases. For BIP39 seed phrases its 128 bits of entropy. Either way, 12 words is perfectly safe.
Let's say that instead of seed phrase we are talking about passwords. If you had to choose between a 12-character password and a 24-character password, which one do you think is more secure and "stronger"? It's kind of obvious, right?
This is a false analogy. Obviously a longer password is better, because when picking passwords most people will use a limited character set of somewhere between 26 characters (lowercase letters) and 95 characters (printable ASCII characters). A seed phrase picks from a set of 2,048 possibilities, and will always have a maximum security of 128 bits, since this is the maximum security of any private key on the secp256k1 curve that bitcoin uses.
