Passkeys are randomly generated passwords that are required to be managed by a password manager. All the major password managers support them, including Apple, Google, Microsoft, Mozilla, and 1Password.
By requiring the passkey to be managed by a password manager, you get some anti-phishing protection. A passkey includes metadata, including the website domain that created it, and the password managers simply won't provide the passkey to the wrong domain. They provide no way for you to copy and paste the passkey into a website, as you can with a password; there's no social-engineering technique someone can use to get you to copy and paste your passkey to an enemy.
A passkey manager is morally required to do an extra factor of authentication (e.g. fingerprint, Face ID, hardware keys, etc.) when you login to a website, but the website has no way of knowing/proving whether that happened; they just get the password.
You reset your passkey the same way you reset your password, because passkeys are just passwords that have to be managed with a password manager. Some sites make it easy to reset your password, some make it hard. You know the drill; there's nothing new or different there.
If you're happy with your password manager, there's no real need to switch, but even very "sophisticated" password users have been known to fall prey to social-engineered phishing attacks.
Are you sure you're never going to copy-and-paste your password into the wrong hands? I don't trust myself that much.
Passkeys can make it harder to switch password managers because the password managers are designed not to let you copy-and-paste a passkey, including from Google's Password Manager to Apple's Password Manager. I think all the password managers kinda like that, and there's something good and bad about it.