Think this hits the nail on the head, because to you adding megas and the new Exp Share ruined what little difficulty was left in-game while to me and others it's a lot like multiplying by 1: nothing changes by making an easy game easier. Emerald wasn't that hard of a game, Mudkip can solo the whole thing so your challenge autmatically takes a step down based on "did you pick Mudkip or not?"
While the Pokemon battle formula can be fun, challenging, and engaging, that mostly comes from either post-game challenges or the metagame. Because in-game most trainers and bosses have only 3 pokemon, barely switch, and have such type-theming that my high school cliques would call them cliche. In this game, advanced AI is "use supereffective attack, and if not use most powerful STAB".
Any challenge in-game comes from 3 areas:
1. Lack of info - that you don't know what a pokemon is, what moves they have, what ability they have, etc. And you waste turns trying to figure it out.
2. Lack of availability - that the perfect counter to whatever challenge you face lies after you face it. The ice beam isn't until after the dragon gym leader, there's only one fighting type and you have to do an in-game trade for it, etc.
3. Time cost - that the effort to train up or create your perfect counter is higher than what you're reasonably willing to commit to. Sure there's an ice type for those dragons, but you get it at level 5 when the gym is level 40.
And as you can probably see, all of these are in the realm of "fake difficulty" where the game isn't giving you a fair challenge but more frustrating you by limiting your options. Because all three are pretty easily broken (use the internet to look up what pokemon it is, trade in pokemon you want). The only one that's harder to get around is the time cost, which is a pretty big deal as the hassle to train up brand new pokemon does discourage the player from shuffling their team too much. I believe its the primary reason the Exp Share changed, as it makes subbing in new pokemon less of a resource drain and grind to get them in fighting shape.
Heck, the Johto games are some of the hardest but I doubt any of you would say it's a fair challenge. Whitney is the perfect little example of it, all of her difficulty is because there aren't enough trainers to overlevel her and only Geodude and the Machop you get in a trade will reliably counter her Miltank.
So as much as you bemoan creating your own challenge, that's been the name of the game since day 1. Even in the original Red and Blue your difficulty was determined by which starter you chose (Bublasaur for the easiest time, Squirtle for medium, Charmander for the [relative] hardest). This entire series is founded on managing difficulty around what pokemon and tools a player will and will not use!
Because Gamefreak has made it loud and clear, delivering a challenging in-game experience isn't their creative priority. They wanted the thrill of exploration first and foremost, everything else secondary. So whether you like it or not is one thing, but singling out ORAS for being too easy is missing the forest because of the trees: they're all easy unless you're going into this series completely blind.
You don't have to like it, but complaining about one iteration in a series plagued with it doesn't seem fair.
First, the exp share was reworked because soloing the game with one mon became the dominant strategy on pretty much all the games on the franchise, but only let's go, out of all games, realized that they had to cut down the amount of exp received to both make sure your entire party doesn't get overleveled and to makes sure that soloing the game is a less effective strategy, the other games just forgot about that and also didn't designed the game around that exp grow, making what was an already easy game straight up boring.
Second, I know the games are a joke, there's a reason of why i only actually respect 3 out of all the mainline games, and even then those are flawed too, pokemon itself is a flawed franchise, 1v1 turn based combat on what is supposed to be a team based game is horrendous, not only because there's no reason to ever have a full team because they basically become exp thiefs, but also because there's barely any strategy, it's basically just brute forcing your way through and/or cheesing everything with X items. The differences in the combat quality between colloseum and most of the mainline games is so high that it's not even funny, which is why i think that the franchise should focus on doubles only, because 1v1 on the story is just fundamentally flawed.
Third, just because something was easy, doesn't mean that i shouldn't complain that they are making it even easier, for example, kirby games are already easy, but also really fun, but now on this new game you never take knockback, never lose an ability and have 50 hits per life, making the game extremely boring, we shouldn't be allowed to complain because "it was already easy anyways"?
Fourth, lack of aviability is bad game design and it is another reason of why i only respect platinum and gen 5, those games actually gave you options while on jotho for example, you literally have nothing viable besides your starter, which ends up on the player always steamrolling the game with it because there's 0 reasons not to.
Fifth, just like grinding, using online options to obtain extremely overleveled mons should never be taken in mind while judging both the game's difficulty and the aviability of said mon, because they both destroy the design of any game.
Sixth, if we use the logic about the games only being challenging because of blindness, then my point still stans, while RSE requires you to know about strats and to pass across battles like the second may fight on the bridge in order to steamroll it, ORAS pretty much breaks itself, so while RSE is only any challenging because of blindness, ORAS isn't even that, as you get way too many tools, making stuff that could mean something on a blind run a complete joke.
Seventh, no the games aren't designed with that in mind, or at least they aren't anymore, as the exp share has become a permanent passive since let's go and starter's choice has been meaning less and less as time went on. The games are designed for young players to be able to beat it, and veterans that were left wanting more just made their own rules, but those rules are not part of the design itself. Im not against selfchallenge runs, i have done multiple of those on a lot of different games, but they aren't of the game itself and judging the game based on it is like judging a notebook based on the stickers it has, even though you were the ones who put those stickers.
I have more to say but i don't have all the time in the world right now, so have my two cents.