Surviving the Passwords.app change with sanity intact

As far as I can tell, Apple now wants me to use their new Passwords.app instead of Keychain, which I've used daily for almost 20 years. They appear to be forcing the issue by not letting me add new items to Keychain. I can open the program just fine but can find no option to add a new keychain item.

And despite lots of online wisdom insisting that my couple decades of accumulated Keychain passwords should just show up in the Passwords.app as long as I'm connected to iCloud and have the passwords option enabled, that has not worked either.

As an aside, this is a rather bizarre thing about Passwords.app that doesn't inspire much confidence: it does show a couple dozen passwords that appear to be from my past... from over a decade ago! Like, super super old passwords for sites that don't even exist anymore and for jobs that I left 8+ years ago. How in the world did Passwords.app only manage to find this small group of useless garbage instead of the **** I really need?

Besides the non-functioning auto-sync feature I keep finding information online saying that I can export passwords from Keychain. However the "export items" menu item in Keychain remains grayed out no matter what group of options I select. Also, Passwords.app insists on only working with a CSV file; it can't parse a keychain-db file. Seems like a pretty bad oversight there. I have not been able to find any way to generate a CSV of my historical passwords.

I've been at this for weeks now and I'm worn down to a whimpering pulp trying to figure out how to not spend the rest of my adult life trying to remember which password app I stored a password in (it's even worse because I mostly use Google Chrome's password storage due to the excellent browser integration... but there are passwords I don't want the browser to remember, so I've long used the browser storage with Keychain as a backup).

I'm starting to think that I'm just going to have to put aside a weekend and manually go through each keychain entry and recreate it in Passwords. That is dumb and annoying and a really lousy way to treat your longterm customers but if that's what I have to do, I'll do it. Any suggestions for avoiding that nightmare welcome!