While that's true because you have a single point of failure, I think it's more likely that your passwords get leaked through site security than 1Pass security

While that's true because you have a single point of failure, I think it's more likely that your passwords get leaked through site security than 1Pass security (depending how you sync/if you use their cloud version) so it's still more (not the most) secure because if they find your password in a database they still don't have your 2FA code.