I understand that Schnorr signatures provide an improvement on ECDSA in that they are a fixed 64 bytes instead of the longer ECDSA sig format, however, I don't see how this is an advantage over ECDSA in any situation except multisig.
With ECDSA, transactions can be signed & verified without needing to include the signer's pubkey in the message. However Schnorr (as described in the recent BIP) doesn't have that advantage, which means that for any transaction not from a multisig address, the necessary space to store all data necessary for verification would be 26 bytes cheaper under ECDSA (assuming a 64 byte Schnorr sig with a 33 byte compressed pubkey vs a ~71 byte ECDSA sig without a pubkey).
With regards to that, why is Schnorr receiving such focus? Do multisig transactions make up enough of Bitcoin's load that Schnorr would be that significant? And why has there been little to no focus on implementing transactions without storing pubkeys (which ethereum has been doing all along)?