...I'm seriously starting to doubt whether you've played adv to the extent you think. Suicune is very similar to GSC Zapdos in that it simultaneously poses as a strong defensive pillar and a huge offensive threat, and it also has the power to beat its checks over the course of a game- in fact, Suicune is even more capable of that feat because Pressure stalling is far more reliable than hitting consecutive Thunders. This is why Rest is actually a good thing for Cune and any seasoned ADV player knows this. To go any further would be taking this comparison too far, since they exist in completely different meta's and are completely different pokemon. But the point is they both achieve similar things. Secondly, locked movepool? Last time I checked the only 2 moves that are mandatory on a Cune set were Calm Mind and a STAB move (a trait that Jirachi, a renowned "versatile" pokemon shares)- the rest of it's set can be a number of things- Rest/Roar, Rest/Ice Beam, Resttalk, Sub/Ice Beam, or even Ice Beam/HP Electric. That's more than enough options to pose a multidimensional threat, and they all require different methods to overcome. You are right that removing Cune would have less effect than removing GSC Zap, but not for the reasons you think. As I already said, Cune has many viable sets that it can run, and they perform and threaten in different ways. In fact, between its sets it can get past any pokemon in the game. Zapdos, while being amazing, does not have that luxury. Like I said earlier, the comparison doesn't apply. It has no way around Raikou (unless extreme parahax), and thus it probably owes its high usage to Zapdos' existence. Suicune has sets for Blissey, for Celebi, for Zapdos, for Regice, for Gyarados... can you see the problem? Theres not a way to beat all Cune sets with one poke, and things that do give most Cune sets trouble (Zapdos, CMBlissey, Raikou) will run those sets regardless because they're so effective in other common scenarios. If any change were to happen, it'd probably just be the things that Cune walls getting more prevalent, such as TTar, Flygon, Mence, Aero, and Pert. Especially Pert.