Yes, this is a huge omission, because it means that as engines improve, the stated advantage becomes increasingly meaningless to humans (which is the opposite of what we may intuitively expect).

What I really want to know as a player is how easy it will be for me to win from this position against someone of my opponent's strength, which is admittedly a very hard thing to define, let alone compute.

How likely you mean. It's the same effort to win a game as to lose a game.