You. You are the single point of failure; if you are compromised, then all your accounts can be accessed by the compromisor.
If you're looking for a point outside yourself, then memorising all your passwords would be an option.
But beyond that, I don't think your criticism is warranted. There's always a single point of failure - sure - but we can still consider gradations of how centralised that point is, and how likely it is to fail.
With a hosted password manager, you're at the mercy of their server code; specifically, at least for 1password, I think they have a 'dead man's switch' which lets you get at the encrypted content without the master password. This is more likely to fail than a password manager which stores all its content locally and really encrypts it (e.g. keepass). In this case, human error outside of yourself can't compromise you. But technical error can, which is why there are more steps that can meaningfully increase your level of security. Like running your password manager on a separate, air-gapped computer; or sandboxing everything you run a la qubes.
Are any of these especially likely to compromise you, as a user? No, but reducing centralisation and dependency still improve your chances, and are definitely worth considering if you are e.g. running a drug smuggling ring.