Charizard-X is absolutely A+ rank material, heck I'd even consider it for S rank if it wasn't for the crippling SR weakness. It just needs a couple of things like Hippowdon and Slowbro weakenes and it can usually just sweep teams completely. And while it's not quteas good in practice as it may seem due to Flare Blitz recoil making pivoting bewteen a Flare Blitz target and a Fire-weak Pokemon one way you can beat it, but not only do you need to predict perfectly, but the team becomes severly weakened as a result so XZard has still done its job.
As for XZard being medicore without a Dragon Dance, that isn't true at all. It has a fantastic typing which enables it to check and counter the likes of Scizor, Ferrothorn, YZard, Sableye, Thundurus, Rotom-W, Manectric, Celebi, Volcarona, Mew, Raikou, Jirachi and more, all the while hitting ridiculously hard. I'd argue that Mega Gyarados is far less threatening than Charizard without a boost : it's slower, weaker, has no recovery, and is much easier to check. And from experience, XZard can find a lot of opportunities to set up thanks to its access to recovery which is a huge advantage over MGyara. And this immediate offensive presence lets it weaken its swicthins more easily, which in turn enables it to more consistently put in work against teams it knows it cannot sweep than MGyara or, let's be honest here, Offnesive MAltaria who doesn't really wall that much with full offensive investement. So yeah, please don't drop XZard, it's a beast and well deserves A+ rank.