Except for the times he played as right back (and when he was young he was a fearsome defender) Gerrard was primarily an offensive player especially starting from Rafa’s time onwards. Therefore he fulfilled his primary objective, and high is to attack far more than defend. He was the classic no 8, not a no 6. So I firmly disagree that he was overrated.
That’s like saying Messi is overrated because he is lax in his defensive duties.
If anything he was underrated. Look around the world game, there is nobody with his set of attributes. He was a rarity.
Where as with Trent his primary job is as a defender, at least starting at right back. I know I know, the nature of the fullback in the modern game blah blah.
Well, you have to at least be able to defend better than he does.