That sounds awesome, and I personally want to self-host nothing. I do enough of that at work.

I do not want to self host either, for exactly the same reasons.

However, I do want to have full control of my secret data beyond the secrets themselves, ideally w/out self hosting, i.e. I want to have crypto-proven control over whom I'm sharing secrets with, I want to have have cryto-level assurance that the service cannot use recovery/escrow mechanism to unlock my secrets data stored on the cloud w/out my consent.

Apple Passwords comes closest to what I want, but it's not cross platform.