Probably asked a million times but honestly getting back into the "game" should I just start off with x/y instead of oras? I recently got sapphire and while I love the updates I feel like i'm going through the motions since I was kinda meh on it back then. Heard X/Y was more of a change due to character customization and apparently a different flow story wise and game wise? At the same time I know this is the newer one and most likely will get actual add on content going forward over x/y. Idk.
The biggest difference by far between X/Y and ORAS is that X/Y has far and away the most varied and expansive lineup of available Pokemon in the series. There are 300+ Pokemon available for capture before the Elite 4 (as opposed to the usual # of something like 100) and you'll be seeing even more than that through battles - it's pretty far removed from ORAS's comparatively limited variety and repeat Pokemon sightings.
I personally really enjoyed the Kalos region but some people find it really boring and I'm really enjoying how Hoenn is presented more. But just the sheer variety of Pokemon on show kept X/Y very engaging to me. In fact, while a lot of people complain about the EXP Share and its new mechanics, I found it extremely useful, because you've basically run into multiple instances of every elemental type of Pokemon (even dragons) before you've even hit the third gym and EXP Share enables you to train multiple teams of Pokemon in the same amount of time it would take to train a single team in any other Pokemon game. By the Elite 4 I had 40 Pokemon at level parity with opposing trainers with nary any grinding.
After playing through X/Y and making extensive use of online functionality (which is at the forefront of the ui at all times if you choose to use it, and it's expansive as hell) I had a massive stock of babies from breeding and trading that I hadn't used. So I moved them over to ORAS and between using Dexnav to search for better versions of Hoenn native Pokemon with secret moves/abilities, and my X/Y leftover Pokemon, I've now got an even bigger active roster of 45 lv40+ Pokemon in ORAS (I'm just past the 7th gym and trainer Pokemon are level 40-43, for reference).
X/Y also puts a fair bit of emphasis on character customization, it's nothing massive but it's pretty neat and fresh to play through as something of your own trainer. I'd say start with X/Y and transfer some Pokemon over to ORAS when you're done. Or, use Dexnav to search for better versions of Hoenn Pokemon in ORAS, you might be surprised just how many Pokemon have really awesome hidden moves or abilities.