I store the printed credentials to my password manager and my e-mail account in a safe deposit box (without mentioning on that paper what the codes are for).

Then I store a YubiKey which is a second factor to these accounts in another safe deposit box in another location.

So should I forget my master password: drive to box 1.

Should my house with all my computers burn down: drive to boxes 1 and 2, find a pc or phone somewhere, and I have access to all my accounts.

Should my password manager go bankrupt overnight and take my vault with them: drive to boxes 1 and 2, then click “forgot my password” on all services and use my e-mail to recover access.

Should my password manager go bankrupt overnight and take my vault with them, my e-mail provider go bankrupt overnight and take my mailbox with them: at least I have my own e-mail domain, so I can set up a new mailbox elsewhere

Should my password manager go bankrupt overnight and take my vault with them, my e-mail provider go bankrupt overnight and take my mailbox with them, and my domain registrar go bankrupt overnight and take my domain with them: yeah…then I’m screwed. I’ll migrate to a wooded country and become a hermit.

Could you help me understand, that if you are this considerate and comprehensive about your risk factors and prepared at all sorts of possibilities, why still use a password manager solution that can "go bankrupt overnight and take my vault with them"? Why not just use KeePass and manage the vault yourself? If your answer is "I only need to do these safe box things once", then writing your own scripts to sync KeePass database between your devices is also only needed done once, right? Even if it's more hassles, considering you will never have the last 3 bullets listed, isn't that worth the trouble?

Because I think my password manager is far more competent in keeping my safe available “in the cloud” than I am in keeping my safe available.

But the password to your domain was in the password manager.