So....yeah, people have playtested them and this SD EX is crap. The worst we've had so far, being more fragile than BW or Shiranui as a Synchro deck, and lacking recovery.
After Neos Fusion and RE Fusion, there hasn't been any SD that makes a real impact on the meta.....
Ascalon can't OTK as good as Vajrayana, and can only blow up monster, not backrow. And is easier to out than Shiranui's boss Synchro. And unless you use Level-changing skill, the deck is prone to bricking, unable to bring out Ascalon, but using such skill makes it weaker against meta decks like Darklords and Elementsaber.
So really, I think Konami feared having the incident with Neos Fusion happening again, so they've been overly careful with SD cards, especially EX ones, making them weaker and weaker.
Almost nobody used it anymore. At most, perhaps only like, 5-10 players are still attached to the deck, out of thousands. It's no longer meta, or even tiered.
It absolutely needs the pre-nerf Master of Destiny to function well, since it lacks consistency and reliability otherwise, not to mention recovery. And as I said, monsters it cannot destroy really makes its usage drop.
i'm not saying people are using the structure deck anymore just that people still use desperado. it's sprinkled into lots of other decks, same as neos. bm-blast spider too since it works as a summon for it and the effect is great.
red eyes fusion is an okay card but red eyes wyvern and the support traps are the real MVPs of that deck. super easy to summon slash without using REF after all.
Wyvern was out for along time (From Crimson Kingdom), it wasn't used at all, less so than spirit. It really is Red Eyes Fusion that takes the deck to another level. It's not about how easy it is to summon Slash, it's that RE Fusion does it as one card, whereas you have to go -1, -2 if you use other methods.