Many informed customers - perhaps most - use the same passwords on many sites because it's too hard to remember hundreds of passwords.

I don't think they're particularly informed if they aren't aware of password managers.

I'm aware, I just can't be bothered. Every time I create an account I ask myself "do I care if this gets compromised?". If the answer is no, then it gets a standard password.

As long as you understand that when that site gets compromised, all other sites where you use your standard password get compromised for you as well. Collectively, all those sites getting compromised for you may be enough of a reason to consider password managers.

They may be informed and "aware" that password managers are a pain to use compared to using the same password for every site.