Not true. Consider the following example:
Two players are playing, heads up. Both players always play every hand, and there is always exactly one bet and call per betting round. Under this scenario, the EV for each player is 0, since we could expect them to both win half the hands, and importantly, win exactly the same amount of money each hand.
Now consider a second situation in which player A plays every hand the same way, but player B folds with the lowest EV hand before any additional cards are revealed. (in hold'em this is 2-7 offsuit). What happens is that player B is losing less money with their worst hand than player A. And since this is zero-sum, it means player B will expect a very slight profit.
Now, extrapolate this to player B only playing +EV hands, while player A doesn't even look at their cards and plays every hand. The following betting rounds still proceed the same way. Player B will be losing a small amount - the ante - on poor hands, and willing a much larger amount with their good hands.
This gets to the heart of my argument - that skill in games like poker or backgammon - will inexorably prevail over a long enough timeline. Sure, player A might catch a great string of cards and beat player B sometimes. But play enough and player B will eventually dominate player A even if no other decisions are made.
This is all, of course, just a thought experiment, but it's meant to illustrate that skill in poker is equivalent to making +EV decisions in the face of incomplete information.