Peope do read, if the email is short
On what grounds you say people dont read? Any evidence?
This premise seems flawed.
How can you possibly know from experience that something is “very understandable” if the only brain you have is your own?
How do you anticipate how other people with brains different from yours are going to behave in situations of cognitive impairment or extreme stress, things that happen in the real world?
(The OP says one time codes are worse than passwords. In case of fishing passwords fail the same way as one time codes.)
I was also sarcastic/provocative even in the prev comment, saying the GOOD site always includes a warning with the code making the attack impossible. A variation of the attack is very widely used by phone scammers: "Hello, we are updating intercomm on your appartment block. Please tell us your name and phone number. Ok, you will receive a code now, tell it to us". Yet many online services and banks still send one time codes without a warning to never share it!
The fishing point may also be used in defence of one time codes: if the GOOD service was using passwords instead of one time codes, the BAD could just initiated fishing attack, redirecting the user to a fake login page - people today are used to "Login with" flow.