Do you only use Apple devices? Despite spending most of my time on a laptop with macOS, I also have a gaming PC with Windows, a home server with Debian, a mobile device with Android, and a tablet with iOS. It's nice to have a bit of flexibility available.
If you use an alternative browser such as Firefox you lose access to the built-in integration.
I think their SaaS offering has vault sharing for friends and family, which isn't available through iCloud Keychain.
They provide additional security audit features, such as vulnerability tracking. Quite relevant: I just opened the app and Watchtower had a vulnerability alert notifying me to update my password on Twitter.
It supports One-Time Password, which can occasionally be convenient.
Other kinds of item are supported as well, such as credit cards, bank accounts, software licenses, identities, and secure notes. No more having to grab for my wallet when I need to input my credit card or driver's license info. No more having to search for a checkbook to find my bank account number.
Not particularly, if you don't need the 1Password features and use Safari on macOS. The password generation is integrated into the browser UI which is arguably better for non-nerd and lazy-nerd users.
I use 1Password to store everything. Security answers so I can use completely bogus ones, social security numbers for family members, software license keys, membership info, etc.
iCloud Keychain is definitely well-integrated, but I've run into a few edge cases where it doesn't behave the way I need it to. In these cases, 1Password is better since it actually lets me dig in and edit some of the low-level details in a quality UI (versus digging a couple levels deep in system settings/Safari preferences to find/edit the password in question).
Do you only use Apple devices? Despite spending most of my time on a laptop with macOS, I also have a gaming PC with Windows, a home server with Debian, a mobile device with Android, and a tablet with iOS. It's nice to have a bit of flexibility available.
If you use an alternative browser such as Firefox you lose access to the built-in integration.
I think their SaaS offering has vault sharing for friends and family, which isn't available through iCloud Keychain.
They provide additional security audit features, such as vulnerability tracking. Quite relevant: I just opened the app and Watchtower had a vulnerability alert notifying me to update my password on Twitter.
It supports One-Time Password, which can occasionally be convenient.
Other kinds of item are supported as well, such as credit cards, bank accounts, software licenses, identities, and secure notes. No more having to grab for my wallet when I need to input my credit card or driver's license info. No more having to search for a checkbook to find my bank account number.