Disagree'd. Injustice 2, for example, reveals frame data right there in the UI. Most any fighting game tutorial for newcomers will begin with frame data and go into detail about 'safe on block' etc
If he's losing a lot, then we need to offer constructive criticism on what they can improve on
I'm going to disagree again. Yes, frames are important, but there is a sense of applying pressure and then defending from pressure. If you've played a lot of fighting games, then you're absolutely aware of when it's "your turn" because of some opening that the opponent has given you.
I'm not sure if Injustice 2 is a good example of what you're trying to imply, as it heavily involves zoning and gimmicks more than some other fighters. Street Fighter V has a very clear turn structure where it becomes important to learn when it's time to apply pressure. This game is extremely similar. After certain strings or patterns, it's very clear when to apply an offense versus when it's time to act defensively.
That is, unless you're playing against 16, then heaven help you...