I know this idea is a little ridiculous, but it just popped into my head: what about using one of those rubber ducky USB keys that pretend they're a keyboard and enter certain keystrokes? You could have it enter the password when inserted.

Or, perhaps a physical password manager that can store multiple passwords, with a labeled button for each?

I'll have to look into that -- it might work.

I don't know which brand you looked at but I'm pretty sure Chromebooks support fingerprint login for some time now (check this HP support page for ChromeOS for instance [0]).

But I agree with the overall tone of what you're saying and I have the same kind of problem with my parents. I think the movement away from common protocols just made it worse, before you could have a simplified client just for the elderly or any other "niche" group and it would work, now if you do something like this for Whatsapp or Instagram you would probably receive a cease and desist letter.

[0] https://support.hp.com/us-en/document/c06917763

FWIW, fingerprint login has never worked for my elderly parents. The combination of drier skin, shaky fingers, and poorer sense of pressure means they could never get it quite right. (And on iPhone, always ended up pressing the home button.)

I’ve noticed in the last decade that my fingers too have less oil and I sometimes have to wet my finger.

I have the same problem with my parents and I initially thought the Windows 10 pin screen was quite good for this. You only need 4 numbers, I set it to my birthdate and it's made things somewhat easier for them.

That was until my mom phoned me telling me her keyboard was broken. Took me a while to diagnose that she was trying to enter letters into the pin-field and it gave no indication that you weren't supposed to do that, it just didn't input any characters.

Also turns out the Windows account metaphor has gotten really confusing since they introduced microsoft accounts that are both local and online but don't necessarily share the same characteristics and now you have like 3 different passwords for the single "account" concept.

You might want to try him with a password manager.

It seems tempting to solve technological problems with more technology, but my experience is more technology is more problems. The password manager will update/ask for updates. It will ask about auto fill or saving passwords, etc. The people with password understanding problems definitely don’t understand password management problems!

1Password has worked well for my 90-year-old mother. I disabled the "ask to save password" option. If she needs a new account on something - which doesn't happen very often - I just use Screen Sharing (we both have Macs) and set it up for her. I also have her 1Password account syncing to mine. Although I do still get support phone calls when there's a glitch, it's worked out very well on balance, compared to the amount of support she needed before with account setup and not using the same password everywhere.

Syncing the passwords to your own computer so that you can set them up is a genius idea.

Unfortunately, Chromebooks also disable perpetual screen-sharing (in order to prevent very-real scam behavior), too. :-/.