Example: Name any other password manager that can instantly spawn disposable email addresses on your own domain by talking to your email provider.

Not to put too fine a point on it, but I fucking love this feature.

It fits in naturally with the password manager, but it has barely anything to do with password management.

Hide My Email in iCloud.

https://support.apple.com/en-gb/HT210425

Note that I said on your own domain.

iCloud email hiding generates addresses on iCloud domains, i.e. services will begin to flag them as a commonly-used disposable address provider and disallow them.

Also completely worthless to the vast majority of people who are not on Apple devices.

Also also, 1Password's integration with the email isn't managed by them. They talk to Fastmail, Fastmail spits out an address and tells it to 1Password, who then fills the form with it. I can ditch 1Password at any time, even delete my account, and lose nothing.