I have never heard of any service or device implementing this either.
The case where an attacker is present and forcing you to login is pretty unlikely. They are more likely to just take your $1000 iPhone and run.
However, it is very plausible for this to happen if the "attacker" is a security guard/TSA officer at an airport security checkpoint. Especially if you are in a foreign country. (There was a PHENOMENAL Defcon talk on this subject a few years back.)
It probably wouldn't make much sense to implement this on a website. If you (the admin) are certain that someone who is attempting to access an account is a hacker, just block them/lock the account. Problem solved.
If the attacker is trying to access multiple accounts, they will probably know something is fishy if they are able to "successfully" login to multiple accounts on the first or second try.
While phones don't allow fake logins (?), but you can set them to lock after the password isn't entered correctly n times.
Attacker/TSA agent tells you to unlock phone. You intentionally enter wrong password on 1st try.
"Oh, oops, wrong password..."
You enter the wrong password again on the 2nd try.
"Sorry, my hands get sweaty when I am nervous..."
You enter wrong password on 3rd try. Phone is now locked for 30 minutes!
This of course will not work if you are reciting the password to the attacker, and they are entering it in the phone. And I think most phone lockouts only last for 30 minutes (?), during which time the attacker/TSA agent will do their best to "convince" you to remember the password in a back room.
Your suggestion would be relatively easy to implement on a laptop...
Create 2 or more user profiles.
The first profile you name after yourself (first and last name). You set a picture of yourself as the profile picture. This will be your "fake" account. Set the password as something simple and easy to remember. Put some "personal stuff" in the account (music, pictures of your pet, "work" documents, etc).
The second account you give a generic family member name ("hubby", "the kids", "honey", etc). Keep the default profile picture. Set a strong password. This will be the account with admin privileges on the laptop, and the account which you will use for your important/confidential work.
Now imagine a scenario in which you are forced to login...
You are in an airport in Oceania, about to fly home to Eurasia. Airport security stop you on your way through the terminal.
Security: "Give us your passport and laptop!"
You hand them the laptop and passport. They turn on laptop, and try to login to the account which you named after yourself. Upon seeing they need a password, they demand you tell them the password.
You: "The password is opensea. No spaces."
The airport security enter the password, and successfully enter your fake account.
After looking around for a few minutes and not finding anything that interests them, they log out and try to login to your real account.
Security: "Whose account is this? What is the password?"
You: "That is my kids' account. The password is 123dogs."
They enter the password, but are unable to login.
Security: "That password is wrong! Tell us the correct password!"
You act surprised, and ask them to give you the laptop so you can attempt to login. They hand you the laptop, and you start typing in bogus passwords.
You: "Those darn kids, I told them NOT to change the password! I'm sorry, they were only supposed to use that account for their stupid video games!"
The airport security confer with each other, and then let you go on your way. You safely return to Eurasia without having the confidential information on your laptop compromised.