I think the point about lusers not being able to manage passwords has been argued to death elsewhere, so I won't take issue with that.
me having good password hygiene doesn't stop my data being hacked when someone working at a subcontracting firm to a company I use leaks all my data
What has this to do with passkeys? Are you sending your password in plaintext to the contractor who stores it that way, unencrypted? That's a separate problem entirely. The only benefit I see with just sending them your public key is that they can't leak your private key, whereas if you used one password for everything, and sent it to them, they could leak it.
Am I missing something? Would passkeys offer an advantage over a password manager? What if the website assigns you a password via DH so that users can't pick bad ones or reuse them, would it have the same advantages?
2FA can be super annoying, but again I think it's a separate issue. If I get control of your phone or laptop then 2FA might save you, but passkeys won't.