I think, in response to the OP's question, sure, if we objectively compare them today, we could actually pick out similar points of critique for both games.
But if we look at it from their respective eras as well, FFX was phenomenal at release; a majority of game featured VA (rare for the time), impressive 3D environments, insane production values, breaking away from the ATB system with fairly fun results, and a generally well-regarded narrative.
I personally think FFXIII was in some ways a natural step in the direction of FFX's design philosophy, except the narrative was never quite as well-regarded, linearity was somehow more enforced to serve said narrative, production values were no longer represented by the insane gap in quality of past FFs, and in general the perceived loss of engagement in combat with the auto-battle option.
Today, both games has lost some of its luster since release; so in general, because of the narrative and better perception of FFX, and the international version having a ton of side-content, FFX is usually regarded as the better game.
Also, since we're on this topic, I honestly believe nothing in FFXIII has a number on "To Zanarkand".