No, factors are supposed to have different qualities, such as:
"Something you know"; "something you have"; "something you do"; "something you are [biometrics]"; "somewhere you are [geolocation]".
Passwords are in your head - "something you know".
TOTP codes are generated by a hardware token - "something you have".
If the TOTP codes are crammed into your password manager, then the factors are no longer distinguished by these qualities, but they're now the same factor, and it's not true MFA anymore, whether or not they're split up across devices, or apps.
Actually, they are pretty much split up. To get access to my passwords and TOTP secrets, the attacker needs one of my devices (something I have) and its password (something I know) or my face/fingerprint (something I am).
The whole point of a fully featured password manager like 1Password or Bitwarden is to rely on it instead of the security of the service you're using. And that implies that you must trust the security of the vault itself.
Of course, each device you have is an additional (an equally dangerous) attack surface. However, most people should be more worried if someone hacks into their devices than their Facebook accounts anyway.
2FA via TOTP implies two things: 1) you know a password; 2) you know the seed. This is why people criticize that approach. In practice, knowing a password and having a file (seed) seem different enough, and work against some phishing threats.
Logging in through a password manager requires that you know a password (your master password), and have a file (your vault).
