I’ve always read the key to 2FA is that it is comprised ofIt's convenient, but undermines security. 2FA codes really shouldn't be stored together with your passwords. 1password has the same feature, but I think even they admit it isn't as secure as using a completely separate authenticator.
1. Something you have (something running the 1Password app)
2. Something you know (the main password to get into 1Password)
so while those two rules are abstracted up/out into the singular point of failure of 1Password being compromised, unless that happens, everything else you log into can have ridiculously long non-shared passwords whether they have 2FA or not, with the added benefit of you only having one basket of eggs to guard.