I guess now is as good a time as any for them to start using a proper password manager.
Personally, I recommend Keepass - it has multiple clients for all platforms, and you can keep the file in sync with a program of your own choosing, like Dropbox, syncthing or whatever you like.
I'm not sure what you're comparing it to. Keepass is free too, in fact it's open source. In my opinion, local software and database that is under your control is always superior to cloud.
Keepass over Bitwarden offers a lot of plugins and integrations, again, if you want more customization or automation.
But, I would say you can use any online password manager as long as it's end to end encrypted, so Bitwarden is a good choice.
I think your bias may be showing. The average computer user doesn’t even think about using a password manager. It just exists and works in their browser.
Should have say: self-hosting is always superior to cloud hosting.
That statement still comes with a pretty damn big caveat though - you need to have the know-how, the time to invest and the hardware (i.e money) to actually set something like this up.
If all of those are true, then self-hosting can definitely be an attractive option for you.
It's only true for a vanishingly small fraction of the population, though.
Hence, Bitwarden is a pragmatic solution that will be superior for the vast majority of the population.
Most amazingly, this setup is also unexpectedly resilient against merge conflicts and can sync even when two copies have changed. You wouldn't expect that from tools relying on 3rd party file syncing.
I still try to avoid it, but every time it accidentally happened, I could just merge the changes automatically without losing data.
KeePass: Will ask you if you want to synchronize/overwrite/discard the database when saving.
KeePassXC: Will autoreload the database in the background, so merge conflicts shouldn't happen in the first place. Otherwise there's 'Merge database' in the menu.
KeePass2Android: So I mixed up the names and this is the client I actually use. This one does all changes to an internal copy of the database that is then synchronized on request.
KeePassDX: As far as I can see it also has a mechanism similar too KeePass2Android.
Assuming you only have one desktop and mobile client you should never run into any issues. If you do have multiple KeePassXC clients it's all fine as well assuming Syncthing always has another client it can sync with.
I would rather lose my passwords than have my password database be accessed by someone else. Most websites have a "forgot password" function, and for passwords that don't have that (e.g. to decrypt my hard drive or log into my computer) I've memorised the passphrase and always type it manually anyway. And for passwords where neither applies, it's probably not a huge loss anyway if I've not prepared for the possibility of losing my password db for that particular password.
All your services should be using https. Vaultwarden in particular won't even run without https unless you bypass a bunch of security measures.
This is how to setup local only and external https, I highly recommend this as a baseline setup for every homelab. It allows you to choose how much security you want on a per app basis and makes adding new apps trivially easy.
If you never, ever need your passwords outside of your home, that's great advice - it's as secure as can be against digital theft. Less so against fire though, and backups are out of the question.
I'm not being facetious though. Off-site backups of a digital password collection are easy to setup and maintain. But when you change your password or add a new entry, it's going to be a pain in the ass to have to drive over and update a physical copy.
If you can live with those downsides, that's fine. But in my opinion it would be facetious to pretend a physical backup is "just as good/usable" as a digital one.
-edit: whoops, misread that as implying that I was being facetious. As you were sir -
You can have backups of physical books. Just copy the text from one to the other. Yeah it is manual work but so is writing the first one in the first place. You can then store the second copy in a fire resistant safe or at a friends or family members house (maybe inside a safe as well).
The thing that makes it worth it to me is long, randomly generated passwords that I don't have to know.
None of the sites and services I use require me to type out a password thanks to browser integration and auto type (for desktop apps and such), along with autofill service on android.
Then along with that I can even store other things like account recovery codes (for 2fa) or security questions (which also get randomly generated answers)... It's a handy thing to have IMHO
If getting a Dropbox account is too difficult for them, I seriously wonder why they'd be subscribed here, or reading articles about password management in browsers.
Never trust your credentials to yourself, you can be bought out by beer, poor decisions, and tripping over the cables connected to your home server you cobbled together.