The first reasoning basically summarises to "storing 2FA token in a password manager protects against phishing because the TOTP token won't be autocompleted on the wrong domain".
Any decent password manager would avoid autocompleting the password on the wrong domain in the first place. I.e.: it will already protect against phishing attacks anyway.
1Password's documentation use to have a whole article about how bad an idea it was to store TOTP in a password manager — but their stance completely changed at some point. Around the same time they started _recommending_ that you do so, and presented it as a key feature in the marketing material.
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Personally, I think that the only valid reason to store a TOTP secret in password manger is when you don't really care too much about an account (e.g.: prefer convenience over security), but the website demands that I set up 2FA.
Any decent password manager would avoid autocompleting the password on the wrong domain in the first place. I.e.: it will already protect against phishing attacks anyway.
1Password's documentation use to have a whole article about how bad an idea it was to store TOTP in a password manager — but their stance completely changed at some point. Around the same time they started _recommending_ that you do so, and presented it as a key feature in the marketing material.
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Personally, I think that the only valid reason to store a TOTP secret in password manger is when you don't really care too much about an account (e.g.: prefer convenience over security), but the website demands that I set up 2FA.