Why is the generation of priv and public keys from bitcoin address archaic but the elliptic curve multiplication and the hash function can rather be used symmetrically? Which looks like the best way for a derivatives
Going of the word "derivatives" do you mean hierarchical determination (HD) wallets as a backup instead of using individual public-private key pairs? The difference here is an antire wallet can be store on a piece of paper/ahead of its use which can be used as a full backup without any risk of losing funds/keys because you've not backed up since your keypool got full/didn't print that private key.
There's also an argument for error reduction in HD wallets as writing down a nmemonic makes mistakes easier to find (electrum is a good example of how this can be done as you can select words as you type them so you'll know a lot of the time if something's written down wrong).