Goodra is honestly crap, its outclassed by florges and sylveon, its lack of recovery hurts it a lot, and there really is no need for a special dragon wall, hence why latias isnt common anymore
Nah, Goodra is actually pretty good right now. It's probably the best special pivot in the current metagame. Its special bulk is nearly unrivaled, and 100/110 offenses are actually really solid, especially considering Goodra has one of the most overbloated offensive movepools in existence. It honestly doesn't care about not having reliable recovery because it doesn't play as a special wall (although RestTalk is far more reliable in XY than it was in BW, and HydraRest is perfectly usable). It also has a bonus of just about shutting down Rotom-W entirely, which is one of the best Pokemon in the metagame right now, while also tanking stuff like Heatran, Jolteon, specially based Genesect, and even Greninja if you're running an Assault Vest set. Very little actually switches into Goodra easily, and it has plenty of switch-in opportunities with its insane special bulk. Sure, it may not be as metagame defining as Aegislash or Greninja, but it's nowhere near "crap."
As for Florges and Sylveon, they don't even get close to outclassing Goodra. Seriously, the only things they have in common are great special bulk, low physical bulk, and very similar special power. Goodra actually has more physical and special bulk than either of them, more speed, much more powerful STAB and coverage moves, and the ability to go mixed with a decent Atk stat. It also has 3 good abilities, while Sylveon and Florges's abilities range from extremely situational to downright useless. Sylveon and Florges are best used as defensive support Pokemon with
maybe a bit of potential as Calm Mind sweepers. Goodra is a powerful bulky pivot with insane coverage and power. They just aren't very similar.
On the note of Latias, it isn't crap either. I've used it a bit on PS!, and it plays pretty similarly now to how it did last generation. It's just that there's a big choice now between Psyshock for killing Florges and Sylveon and Thunderbolt for Azumarill and Togekiss. Otherwise, it's still perfectly solid. The only Pokemon that really destroys it that it didn't have to deal with last generation is Aegislash, since it can switch in pretty and possibly Pursuit trap it. The reason it isn't used very much is simply because everyone is still trying out all the new stuff and experimenting with different cores and team styles. Besides, usage stats have never really been a great measurement of a Pokemon's viability, and trying to measure viability of a Pokemon based on its usage just a couple of weeks into a brand new generation is a terrible idea. If we were going by the usage stats, then Donphan, Jolteon, and Delphox are more viable than Hippowdon, Terrakion, Keldeo, and Kyurem-B, which is just ridiculous.
The only unique thing about Goodra is Gooey. It's possible Hydration sets are outclassed by Vaporeon and it's weaker than Vaporeon when it comes to taking a physical hit.
Vaporoen and Goodra have almost nothing in common besides good special bulk and Hydration. Vaporeon was already mediocre enough during late BW2 because most of the time it just sat there and looked bulky without actually doing much besides Wish passing or statusing a couple of things. The LO Tank set was actually a really cool and underrated set, but it's far worse off now since it needs a steady supply of Rain to keep Resting in front of various opponents and keep tossing off powerful Hydro Pumps. Goodra is a far better offensive pivot with its stronger STAB and far better coverage. HydraRest Goodra is not designed to stay in and wall all day long. It needs just one turn to Rest off damage and switch out for later, and it has
far better synergy with Politoed than Vaporeon, which helps it do just that.
And as far as we know Goodra lacks 3 moves that Vaporeon has: Wish, Baton Pass, Aqua Ring.
Baton Pass and Aqua Ring are honestly really crappy outside of dedicated Baton Pass teams. Wish is all that Vaporeon really has over Goodra as far as recovery goes, and even then, Wish Vaporeon doesn't really do much besides pass Wishes and toss around Scalds. I'm honesty surprised it stayed OU for the duration of BW.
People need to take in consideration weather is hard to do now, you can just slap a politoed on a team with vaporeon/goodra and say it can use rest hydration as the switch is obvious and it can get KOed on the switch in
To be perfectly honest, I've been using that Rain team with Goodra plenty on both PO and PS!, and I've never had this problem. Most of the Pokemon that come in on Politoed are things like Rotom-W, Jolteon, and Heliolisk, which are all laughed at by Goodra. People never really predict that switch perfectly because there are 3 other members of my team I could switch to that are capable of abusing the Rain in some way. The fact that Goodra covers Politoed's 2 weaknesses perfectly only makes the duo even stronger.
plus rain is now the most inferior of the weathers having one inducer with sub par stats.
No, Hail is definitely still the most inferior weather. Hail has never been a very good weather to abuse, and even though Abomasnow has a Mega form now, it's still as slow as Christmas and has a plethora of easily abused weaknesses. I'd say that Sun is easily the second worse. Ninetales has always sucked; at least Politoed has great defensive typing and solid bulk. Mega Charizard Y isn't exactly a perfect weather starter either since it makes Defog/Rapid Spin support even more mandatory than it was before. Sun is also far harder to abuse than it used to be. Chlorophyll sweepers are nowhere near as good as they used to be since they need a few turns to actually get in, set up, and start a sweep. Pokemon like Victini can still abuse the boost to Fire moves, but they don't have the ability to outspeed nearly everything under Sun. Maybe you'd have a point if DrizzleSwim were still banned, but it isn't. Swift Swim users can actually abuse both the boost in speed
and a 1.5x boost to their STAB moves. Specs Kingdra is great right now since it has such great typing, outspeeds pretty much everything, and can hit hard from the get-go with Specs Hydro Pumps and Surfs. I can't tell you how many times I've sacked Politoed and swept with Kingdra with the remaining 4 turns of Rain (and it often doesn't even need that many). No Sun Pokemon can abuse both the speed boost of Chlorophyll and the STAB boost of Sun at the same time like Kingdra, Kabutops, etc. can do in Rain. Rain is nowhere near as good as it was last generation, but I'd say it's in about the same rank as it was in late BW2: second only to Sand.